Correct option is B
The correct answer is eyes are fixed and cannot move.
The birds move their neck very often because, in most of the birds, the eyes are fixed and cannot move. Most of the birds have their eyes on either side of the head. Birds' eyes can focus on two different things at a time. When they look straight ahead, both their eyes focus on the same object. In most birds, eyes are fixed and cannot move. So birds have to turn their heads to see around.