This is a question on a worksheet that I'm giving to a student:

A man of weight $W$ steps into the lift. The lift then moves downwards with a constant speed. If $R$ represents the force acting on the man by the lift floor, which of the following statements is/are correct?

(3) $R$ and $W$ are an action-reaction pair according to Newton's third law

Why isn't this statement (3) correct?