The key distinction: investigation diaries can be used by courts to aid inquiry BUT NOT as evidence. They can also be used by the police officer to refresh memory. Statement C ('may be used as evidence') contradicts Section 172(2) and is therefore incorrect.

1. 1 Pick up CrPC.
2. 2 Go to Section 172 — Diary of proceedings in investigation.
3. 3 Check each option:
4. 4 - (A) S.172(1A): witness statements inserted ✓ correct
5. 5 - (B) S.172(1B): diary duly paginated ✓ correct
6. 6 - (C) S.172(2): diaries may be used by court 'NOT as evidence' but to aid inquiry → this is the INCORRECT statement
7. 7 - (D) S.172(3): police can use to refresh memory ✓ correct

The text reads: Section 172(2): Court may use diaries NOT AS EVIDENCE but to aid inquiry or trial.