When is the court likely to dismiss a case under FRCP 12(b)(7) for failure the plaintiff's failure to join a defendant as a party? 

 a) When the party is a necessary party. 

b) When the party is an unnecessary party.

c) When the party is an indispensable party because the court determines that the case should not go forward without them under the equity and good conscience test. 

d) When the party is not diverse from the defendant