Is the nonce in Bitcoin the answer to the puzzle from the previous block? If, in Bitcoin, the nonce is included in the header of the proposed block, is it the answer to the puzzle from the previous block?
Nonce of a header is the answer to that block.

Recall the mining process:


Create a template block header
Choose a nonce
Hash the block header
If the hash is lower than network difficulty, broadcast it. Else, choose a different nonce.


To sum up, nonces are for individual blocks, and a different nonce is chosen until the template becomes a valid block.