Identify the Sequence of Curved Arrows (Electron Movement) in the Steps

Identify the sequence of curved arrows (electron movement) in the steps of the following reaction.

A) Proton transfer, proton transfer, nucleophilic attack
B) Proton transfer, loss of leaving group, nucleophilic attack, proton transfer
C) Nucleophilic attack, proton transfer, loss of leaving group
D) Proton transfer, loss of leaving group, proton transfer, nucleophilic attack