Answer:
A) free males who had been born in Athens and were at least 18 years old
Step-by-step explanation:
For a person to be regarded as a citizen in fifth-century Athens, such a person had to be male, born in Athens from two Athenian parents and over eighteen years old.
Hence, only males who were at least 18 years old and born in Athens were regarded as citizens of Athens and participated in ancient Athenian democracy.