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.
The meaning of the word alleged is (of an
incident or a person) said, without proof, to have taken place or to have a
specified illegal or undesirable quality. So among the choices alleged is
something similar to word suspected.so the answer is a
