What is the effect of illegality on a contract? Which of the following is correct? A contract if breached by one of the parties, then becomes an illegal agreement and is unenforceable O A contract may be illegal and therefore void, or the agreement may become illegal due to a change in law or cire Illegal contracts are possible, while they may not be enforced, they are still valid and not discharged once they b O If a contract was a legal one, before legislation was introduced to make the subject matter illegal, then the agree