Fatal decision or not?

M did not know where to go. He had some options though. If you take a look in this chess game it was like this:

M is White

Police is Black


W moved F2 to F3

B moved E7 to E6


Now it is White again.

Which move should W not do if he does not want to be check mate in the next round?

Title of the document Write like this "F8toC6"
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