A

Step 1: Understand the configuration of the plates. There are three plates: the leftmost with charge -q, the middle is neutral, and the rightmost with charge 2q.
Step 2: When the -q plate induces charges on the neutral plate, the neutral plate will have +q on the side facing the -q plate and -q on the side facing the 2q plate due to charge induction.
Step 3: The rightmost plate with +2q will also induce charges on the outer surface of the leftmost plate.
Step 4: By conservation of charge, the charge on the leftmost plate remains -q. But since it can induce charges on the outer surface due to the presence of additional electric fields, the outer surface of the leftmost plate will adjust accordingly.
Step 5: Therefore, the charge on the outer surface of the leftmost plate must remain -q in total to satisfy the conditions set by the other two plates.
Step 6: The induced charge on the inner surface of the leftmost plate due to the -q charge will attract +q, and thus the outer surface of the first plate will possess a charge of 0 to maintain neutrality with respect to the surrounding electric fields.
Therefore, the charge appearing on the outer surface of the leftmost plate is 0.