4 .
Another friend comes round to where you are staying, bringing with her a fairly precious book that you lent her some while ago. As you open the door to her, it is clear she has come through the rain, and you are worried about the book; taking out a plastic carrier from her bag, she says,
'I brought you your book back, but I'm afraid it may have got a bit damp.'
Without showing your feelings, how bad a state do you fear the book may be in?
The edges of a few pages may be slightly moist and wrinkled, but half-an-hour on a warm radiator should leave the book perfectly readable.
Several of the pages may be soggy, perhaps stuck together, and the spine and cover may be warped for good.
You may never be able to use the book properly again; and however good her intentions, your friend should either have not brought the book along today in the rain, or now ought to replace it with a new copy in useable condition.
The book is only very slightly and residually damp: nothing to worry about!
Neither of the top two Answers even uses 'please', and the frequently-heard (but nonetheless wrong) 'off of', in Answer 1, is a further mistake.
Answer 4 is probably the 'next best try', but somehow 'that foot of yours' (while trying to be indirect) does sound almost too accusing, even in the circumstances.