Wild Turkeys (Meleagris Gallopavo) Perform Mating Displays at Leks Alone

Wild turkeys (Meleagris gallopavo) perform mating displays at leks alone or in coalitions of related males. In the coalitions, only dominant males copulate with females. Why do nondominant males join coalitions?

A) A nondominant male obtains greater inclusive fitness by helping a brother mate than by mating on his own.
B) A nondominant male obtains greater direct fitness by helping his brother mate than by mating on his own.
C) A nondominant male obtains less indirect fitness by helping his brother mate than by mating on his own.
D) A nondominant male may eventually become the dominant male in a coalition.