Answer:
Correct answer is d. privateer.
Step-by-step explanation:
D is the correct answer because before he was engaged in stopping the Armada Drake was already famous as an explorer, so he was granted a privateer's commission which allowed him the plunder Spanish ports across the Ocean.
Still, when the war with Spain started Drake was called upon to help his country to stop the attack of Philip II.
A is not correct because he was not a sailor, but a sea captain. Also, he was never a mercenary or a common soldier. That is why B and C are not correct.