Question

UPSC Prelims 2026 Question:

Consider the following assertion:

In the Pleistocene period either the Yamuna once flowed into the Indus, or the Sutlej flowed into the Yamuna and one major tributary of either had shifted from the Ganga to the Indus or vice versa.

Which of the following is/are the basis of the above assertion?

1. The Nadi-Sukta of the Rigveda
2. The explorations of the Sutlej and the Yamuna by Robert Bruce Foote
3. The presence of the same species of dolphins in both the Indus and the Ganga river systems

Select the answer using the code given below:

  1. 1. 1 only
  2. 2. 2 only
  3. 3. 1 and 2
  4. 4. 3 only

Answer (Detailed Solution Below)

Option 4: 3 only

Detailed Solution

Explanation:

● The Nadi-Sukta of the Rigveda provides literary references to rivers of ancient India, but it is not considered scientific evidence for river capture or paleochannel shifts during the Pleistocene period. So, statement 1 is not correct.

● Robert Bruce Foote made important contributions to Indian geology and prehistory, the given assertion is not specifically based on his explorations of the Sutlej and Yamuna rivers. So, statement 2 is not correct.

● The presence of the same species of river dolphins in both the Indus and Ganga systems suggests that these river systems were once interconnected. So, statement 3 is correct.

Therefore, option (4) is the correct answer.

Latest UPSC Exam 2026 Updates

Last updated on August, 2026

UPSC Mains 2026 commenced on 21st August 2026 and will continue through 30th August 2026, as per the official examination schedule.

UPSC Mains Question Paper 2026 is out now for Essay & GS Paper 1, 2, 3 & 4.

UPSC Mains GS Paper 1 2026 is out now.

UPSC Mains GS Paper 2 2026 is out now.

UPSC Mains GS Paper 3 2026 is out now.

UPSC Mains GS Paper 4 2026 is out now.

→ Check out the latest UPSC Syllabus 2026 here.

UPSC Mains Admit Card 2026 is now out.

→ Enroll in Vajiram & Ravi’s UPSC Mains Test Series 2027 for structured answer writing practice, expert evaluation, and exam-oriented feedback.

→ Join Vajiram & Ravi’s UPSC Mentorship Program 2027 for personalized guidance, strategy planning, and one-to-one support from experienced mentors.

→ Go through the UPSC Mains Previous Year Papers to enhance your preparation.

→ Download UPSC Mains Essay Paper 2025, UPSC Mains GS Paper-I 2025, UPSC Mains GS Paper-II 2025, UPSC Mains GS Paper-III 2025, UPSC Mains GS Paper-IV 2025, UPSC Mains English (Compulsory) Paper 2025, UPSC Mains Hindi (Qualifying) Paper 2025 here.

→ UPSC has released UPSC Toppers List 2025 with the Civil Services final result on its official website.

UPSC Calendar 2027 has been released.

→ Also check Best UPSC Coaching in India

Abhishek Singh
Abhishek Singh is an SEO Specialist and content strategist with over 4.5 years of experience in driving organic growth across education and service-based industries. He specializes in on-page SEO, technical SEO, content optimization, and data-driven strategies that improve search visibility and organic traffic. His work focuses on creating accurate, well-researched, and search-optimized content that helps students, professionals, and online audiences find reliable information. By combining SEO expertise with a strong understanding of search intent and evolving search technologies, he works to build content that delivers visibility, engagement, and long-term trust.
UPSC GS Course 2027
UPSC GS Course 2027
₹1,80,000
Enroll Now
GS Foundation Course 2 Yrs
GS Foundation Course 2 Yrs
₹2,45,000
Enroll Now
UPSC Mentorship Program
UPSC Mentorship Program
₹69000
Enroll Now
UPSC Sureshot Mains Test Series
UPSC Sureshot Mains Test Series
₹27000
Enroll Now
Prelims Powerup Test Series
Prelims Powerup Test Series
₹14000
Enroll Now
Enquire Now