The correct answer is one main clause.
This means that there is only one verb in the sentence, which in this case is the verb 'was.' Even though drive is also a verb, in this context it is used as an adjective driven (participle form of the verb to drive) and is thus not considered to be a verb. This means that there are no subordinate clauses but rather just one main clause.
Answer:
Simile
Explanation: A simile uses like as or than
I believe young Fredrick Douglass was a bit frightened and afraid to do anything but what he's told to do in his early years of life. He had seen his aunt be tortured and was scared to see that happen to himself so he stayed undercover for a long time.