The correct answer is C) all free adult males.
The statement that offers the BEST description of a person who would have had full political rights in Ancient Athens is "all free adult males."
It was Cleisthenes, a greek politician leader in ancient Greece, the one that came up with the concept of democracy, a political system that allowed citizens to chose their rulers. In the 4th century BCE and under this system, all adult males had the liberty to express themselves with liberty, had equal political rights, and the change to be part of the government.