A person is guilty of sexual abuse in the first degree when he or she subjects another person to sexual contact:

1. 1. By forcible compulsion; or
2. 2. When the other person is incapable of consent by reason of being physically helpless; or
3. 3. When the other person is less than eleven years old; or
4. 4. When the other person is less than thirteen years old and the actor is twenty-one years old or older. Sexual abuse in the first degree is a class D felony.