Final answer:
A verbal contract is called an express contract. It refers to an agreement between parties that is legally binding and does not need to be in writing.
Step-by-step explanation:
A verbal contract is called an express contract. A contract generally refers to an agreement between two or more parties that is legally binding. While some contracts must be in writing to be enforceable, verbal contracts can also be enforceable under certain circumstances.
For example, if two people agree to sell and purchase a car, and they verbally agree on the price, terms, and delivery date, a verbal contract is formed. However, it's important to note that the proof of a verbal contract can be more challenging to establish compared to a written contract.
Therefore, in this case, the correct answer is c. Express contract.