Answer:
One subordinate clause
Step-by-step explanation:
A subordinate clause is a clause (a group of words with a subject and a verb) that does not express a complete thought on its own, and therefore it cannot stand on its own, or be alone as a sentence. Before Samantha can take her driving test a subordinate clause because it is incomplete, it does not express a complete thought on its own.
Furthermore, we can also identify it as a subordinate clause because it is introduced by a coordinating conjunction: before.