Answer:
Option B,C
Explanation:
(a) R is not steam volatile , but Q is steam volatile thus, incorrect.
(b) Q has enolic group thus, gives violet colour with 1% aqueous $FeCl_{3}$ solution thus, correct.
(c) S has carbonyl group hence, gives yellow precipitate with 2, 4-DNP thus, correct.
(d) S does not give colour with $FeCl_{3}$ thus, incorrect.