Answer:
The correct answer is letter "A": voidable.
Step-by-step explanation:
Voidable contracts are those that cannot be enforced because one or the two parties involved are not legally eligible to go on in such an agreement. Reasons to void a contract include but are not limited to failure to disclose material facts, legal incapacity to enter a contract or inconsistent contractual terms.
Thus, Bob's contract to purchase a car is voidable since he is legally incapable of signing agreements due to his age (17 years old).