The correct functional group X and the reagent/reaction conditions Y in the following scheme are

A

$$X = COOCH_3, Y = H_2/Ni/heat$$

B

$$X = CONH_2, Y = H_2/Ni/heat$$

C

$$X = CONH_2, Y = Br_2/NaOH$$

D

$$X = CN, Y = H_2/Ni/heat$$