Oswald, a Minor, Makes a Contract with Albert, an Adult

Oswald, a minor, makes a contract with Albert, an adult, to buy a motorcycle. One week later, Oswald has his eighteenth birthday and shortly thereafter tells Albert he will pick up the motorcycle next week. In this case:

A) Oswald has expressly ratified the contract.
B) the contract must be renegotiated, because Oswald was a minor when it was made.
C) Oswald can change his mind and avoid the contract, because it was made when he was a minor.
D) the contract is void ab initio , because Oswald was a minor at the time it was made.