A
Only one
B
Only two
C
All three
D
None
Correct answer: (b) Only two
Explanation
- A
Only one
Only one. Gold mining and coal plants are both mercury sources.
- B
Only two
Only two. ASGM and coal-fired plants release mercury. A blanket ‘no known safe level’ is not keyed as the third correct limb.
- C
All three
All three. The paper stops at two.
- D
None
None. Two pollution sources stand.
Summary. Official key is (b) only two. Artisanal gold mining (mercury amalgamation) and coal combustion are major global mercury sources. The Commission does not count the ‘no known safe level’ sentence as a third correct statement in this item.
Same topic · past papers
UPSC has asked this before
These previous-year questions sit on the same topic. Open one to practise the earlier ask.