Correct option is B
Given:
- Five friends A, B, C, D and E are sitting in a row and watching the film.
- A and D are sitting at extreme ends while B is sitting exactly in the middle.
According to given information linear seating arrangement will be-

Lets check by options:
Option (a): B sits immediately next to both C and E

We can not say who is sits next to A.
Option (b): C is not sitting next to D
Condition 1:

Condition 2:

In both condition, C is sits next to A.
Option (c): C is sitting next to B

We can not say who is sits next to A.
Option (d): B sits next to E

We can not say who is sits next to A.
Thus, the correct option (b) C is not sitting next to D.