Choose the group of letters which is different from others.

Answer: Option B

Explanation:

All other groups are consecutive letters in reverse order.

Answer: Option C

Explanation:

In all other pairs, second is the head of the first.

Answer: Option B

Explanation:

In all other options second is the form in which first is preserved.

Answer: Option D

Explanation:

All other groups consist of consecutive letters.

Answer: Option D

Explanation:

All except Cabbage grow underground.