Option A is correct: All of the answers are correct.
EXPLANATION:
All of the parts of the body listed above can be affected by poor ergonomics. For instance, the fingers, wrists and hands can be affected by poor posture when using a computer keyboard, or when handling a computer mouse.
Legs and feet can be harmed by what shoes one wears. For example, wearing high heel shoes for too long can harm the toes.
The neck and back no doubt can also suffer from poor ergonomics. For example, when one is in a crooked position when working or doing something, sometimes the back and neck will begin to ache. So of course these parts of the body are affected by poor ergonomics as well.
All-in-all, all of the answers are correct.
