Who founded the Mauryan Empire in c. 321 BCE?

Chandragupta Maurya

The correct answer is Option (4) → Chandragupta Maurya

The growth of Magadha culminated in the emergence of the Mauryan Empire. Chandragupta Maurya, who founded the empire (c. 321 BCE), extended control as far northwest as Afghanistan and Baluchistan, and his grandson Asoka, arguably the most famous ruler of early India, conquered Kalinga (present-day coastal Orissa).