Concerning the Egyptian Queen Cleopatra, it is stated in World History Encyclopedia "she was simply on the wrong side of a power struggle" (Wasson, 2016). Which power struggle is the author referring to here?

A) The struggle for control of the Nile River
B) The conflict between Cleopatra and her brother Ptolemy XIII
C) The rivalry between Cleopatra and Julius Caesar
D) The battle for supremacy among the Egyptian gods