The correct option is A Pushyamitra Sunga
Brihadratha Maurya was the last ruler of the Maurya Empire. He ruled from (c. 187 – c. 180 BCE), was assassinated by Pushyamitra Shunga, who was actually a general of the Maurya Empire. He instigated a coup in 185 BCE, went on to establish the Shunga Empire.