Answer: c. A bilateral contract
Step-by-step explanation:
In a bilateral contract, the parties involved promise to both perform duties to the other which will make them both an obligor and an obligee.
An obligor is one who owes a duty to another and the obligee is one who a duty is owed to.
Aaron both owes a duty to sell the boat to Matt as well as being owed by Matt the duty to buy his boat. The same goes for Matt thus making this a bilateral contract.