What's the difference between "offer" and "suggestion"? I feel both are correct in the following dialogue.

--- If you like I can do some shopping for you.
--- That’s a very kind ______.
A. offer B. suggestion
An offer is an expression of willingness to do something. A suggestion is usually an expression of an idea for someone else to do something.
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Can I take it that we can't choose suggestion in the dialogue?
Yes, you may take that as a conclusion.
Thank's you so mush.
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