Final answer:
Poseidon is the deity who encouraged the Ajaxes to counter the Trojans in Book 13 of Homer's Iliad. He is the god of the sea and wanted to assist the Greeks. The correct option is c. Poseidon.
Step-by-step explanation:
In Book 13 of Homer's Iliad, it was Poseidon who rallied the two Ajaxes to push back the Trojans. Unlike Athena, who is well-known as the goddess of warfare and wisdom, or Apollo, the god of the sun and prophecy, Poseidon is the god of the sea, earthquakes, and horses.
His intervention in the battle is driven by his grudge against the Trojans and his desire to aid the Greeks. Poseidon is a major figure in the Greek pantheon, and his role in this episode is an example of the direct influence the gods have on the events of the Trojan War. The correct option is c. Poseidon.