The First Step in the Following Reaction Is

The first step in the following reaction is:

A) protonation at C-3 or C-6.
B) protonation at C-2 or C-7.
C) loss of a proton from C-3 or C-6.
D) loss of a proton from C-2 or C-7.
E) formation of a bond between C-6 and C-2.