Compounds A and C in the following reaction are ___________ $CH_3CHO \quad \underrightarrow {CH_3MgBr} \quad (A) \quad \underrightarrow {H_2SO_4} \quad (B) \quad \underrightarrow {Hydroboration } \quad (C)$

Question

$\begin{array}{1 1} identical \\ Positional \;isomers \\ functional \;isomers \\ optical\;isomers \end{array} $