Explanation
- A
I, II and III
I, II and III. III fails: GAGAN is not aviation-only.
- B
II and III only
II and III only. III fails, and I is dropped.
- C
I only
I only. II is also keyed.
- D
I and II only
I and II only. Extra accuracy and integrity, and better ATM. Benefits are not confined to aviation.
Summary. Official Set A key is (d) I and II only. GAGAN is India’s SBAS: extra accuracy and integrity for GNSS (I) and more uniform air-traffic management (II). It is also used in other modes (survey, rail, roads). III’s ‘aviation only’ is false. So I and II.
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.