Correct Answer: B

Rationale: Vibratory sense is assessed by placing a vibrating tuning fork on bony prominences, commonly the big toe.

Correct Answer: A

Rationale: Sumatriptan is used to treat acute migraines, not for prevention.

Correct Answer: C

Rationale: Metformin is preferred in older adults and those with a risk of hypoglycemia.

Correct Answer: C

Rationale: Neither frailty index nor Fried frailty criteria includes cognition assessment, as frailty is primarily a physical condition.

Correct Answer: D

Rationale: If a test consistently yields the same result, it should be used when suspicion for the relevant condition is high.