Identify A, B, and C,
i. Isomeric alcohols (A), (B), and (C) `(C_(5)H_(12)O)`.
ii. (A) and (B) react with chromic acid solution. (B) gives an acid (D).
iii. Reactivity with HBr is `C gt A gtgt B` . All give the same compound, `C_(5)H_(11)Br` (E).
iv. Only (A) is oxidised by NaOI.

Explanation

i. Zero DU in all alcohols suggests the absence of ring or `(C=C)` or `(C-=C)` bond.
ii. `overset ((B)) underset (ROH)` `overset (H_(2)CrO_(4)) rarr` Acid (D) suggests that (B) is `1^(@)`
`overset ((A)) underset (ROH)` `overset (H_(2)CrO_(4)) rarr` No acid suggests that (A) is `2^(@)`
iii. Reactivity with HBr suggests, (C) is `3^(@)` ROH. Reaction of (A) with NaOI (Iodoform test) suggests. `(R-underset(OH)underset(|)(C )H-CH_(3))` type of alcohol.
(A), (B), and (C) `overset (HBr) rarr` Same `C_(5)H_(11)Br` (E) suggests that rearrangement is taking place by `H^(-)` or Me shift.
iv. `overset ([O]) underset (H_(2)CrO_(4) rarr` No reaction