Answer
a) Alcohol
b) Ether
c) Alcohol
d) Ketone
Work Step by Step
a) Identify the functional group. Here, it is $-OH$. This is the functional group of alcohol. So, this compound belongs to alcohol group. (more specifically, this is an aliphatic alcohol as the OH group is associated with aliphatic C atom.)
b) Identify the functional group. Here it is $-O-$ i.e. ether functional group. So, this is an ether (specifically, aromatic ether because of two phenyl groups present on both side of O atom)
c) This compound also belongs to alcohol as there is $-OH$ group present.
d) This compound belongs to ketone group because functional group present here is $-CO-$
