what does 'bite his hand off' mean

Mike: ‘He offered me a 50% discount. What should I do?’
Jane: ‘…’

(a) Hold his hand down.
(b) Bite his hand down.
© Hold your hand in.
(d) Bite his hand off.

The correct answer is D, but what exactly does ‘bite his hand off’ mean? It sounds like 'cut off sb’s hand by teeth to me. :frowning:

Hi,

This is an idiom and means: accept the offer immediately, without hesitation. The idea of ‘biting’ suggests dramatically that you should accept the offer that he’s making with his hand and not only grab it but bite it off!

Alan

Thank you for your explanation. :smiley: