To determine why the correct answer is D (S) and why the other options (A, B, and C) are incorrect, we need to analyze the visibility of Bari Hill from different points (P, Q, R, and S). Step-by-Step Explanation

1. Understanding Visibility:
2. Visibility of a hill or any elevated landform depends on the observer's height and the surrounding terrain. If there are obstacles (like other hills, buildings, or trees) between the observer and the hill, the hill may not be visible.
3. Analyzing Each Option:
4. Option A (P): If a person standing at point P is at a sufficient height and there are no significant obstructions between P and Bari Hill, then Bari Hill can be seen from P.
5. Option B (Q): Similarly, if Q is at a height that allows a clear line of sight to Bari Hill, then it can be seen from Q.
6. Option C (R): If R is also elevated and has no obstructions, visibility to Bari Hill is possible.
7. Option D (S): If S is at a lower elevation or has significant obstructions (like other hills or buildings) blocking the view of Bari Hill, then it cannot be seen from S.
8. Why D is Correct:
9. The correct answer is D (S) because it is likely that point S is either at a lower elevation than Bari Hill or is surrounded by other geographical features that obstruct the view. This means that a person standing at S would not have a direct line of sight to Bari Hill.
10. Why A, B, and C are Incorrect:
11. Option A (P): If P is at a higher elevation or has a clear view, it is incorrect to say that Bari Hill cannot be seen from P.
12. Option B (Q): The same reasoning applies; if Q is elevated or unobstructed, it is incorrect to claim that Bari Hill is not visible from there.
13. Option C (R): If R has a clear line of sight, it is also incorrect to say that Bari Hill cannot be seen from R.

Common Pitfalls

• Assuming All Points are Equal: Students may mistakenly assume that all points are at the same elevation or have the same visibility without considering the terrain.
• Ignoring Terrain Features: Failing to account for hills, valleys, or other obstructions can lead to incorrect conclusions about visibility.

Revision Summary

• Visibility of a hill depends on the observer's height and surrounding terrain.
• The correct answer is D (S) because it likely has obstructions or is at a lower elevation.
• Options A (P), B (Q), and C (R) are incorrect as they likely allow visibility to Bari Hill.
• Always consider the geographical context when analyzing visibility questions.