Compound A is an optically active alcohol. Treatment with oxidising agent converts it to a ketone B. In a separate reaction A is treatment with `PBr_(3)`, converting it into C. C on reaction with Mg is added to B to yield
. Identify the correct option.
A. A is 2-butanol.
B. A is 1-butanol
C. C is 2-bromobutane
D. C is 1-bromobutane