What was the name of the princess rescued by Perseus?

The princess rescued by Perseus was Andromeda. In Greek mythology, the story goes that Andromeda was the daughter of King Cepheus and Queen Cassiopeia of Ethiopia. Her mother boasted about Andromeda's beauty, claiming that she was more beautiful than the Nereids, the sea nymphs. This pride angered the sea god Poseidon, who retaliated by sending a sea monster, Cetus, to ravage the coastline.

To appease the god and save their kingdom, Andromeda was chained to a rock as a sacrifice to the monster. Perseus, returning from slaying the Gorgon Medusa, came upon the scene and saw the beautiful princess in her perilous situation. He heroically intervened, defeating Cetus and rescuing Andromeda. They subsequently married and had several children together.

None of the other names listed fit this particular narrative. Hippolyta is known as the queen of the Amazons, Cassandra is a prophetess doomed to never be believed, and Penelope is famous for her fidelity to Odysseus during his absence. Thus, Andromeda is unequivocally identified as the princess rescued by Perseus in mythological tales.