[Poker Dealer] Roland and Parna Sign a Contract for Parna

[Poker dealer] Roland and Parna sign a contract for Parna to work as a poker dealer for a minimum of one year in Roland's casino. The contract includes a requirement for Roland to pay for a training program for Parna for the software system used throughout the casino. Parna completes the program and obtains a certificate. The week before Parna begins work at Roland's casino, their state passes a law that all poker dealers must be 21 years old. Parna, however, is only nineteen.
-Is Roland required to employ Parna?

A) Yes, because the contract was legal when formed.
B) Yes, because the contract was ratified when Parna completed the training program.
C) No, because the subject matter of the contract is illegal, thus it is void.
D) Although the contract was legal when formed, its subject later became illegal under a new statute, thus both parties are discharged from their obligations under the contract.
E) Although the contract was legal when formed, its subject later became illegal under a new statute, thus it is voidable by either party.