Question

spartan soldiers helped save retreating members of the greek army at the battle of marathon. at the battle of thermopylae. against a force of three hundred persian troops. against the strength of the athenian navy.

Explanation:

At the Battle of Thermopylae, a small force of Spartan and other Greek soldiers held off a much - larger Persian army, allowing some Greek forces to retreat. The Battle of Marathon was an Athenian - led victory against the Persians without significant Spartan involvement in the retreat - saving aspect. The Spartans faced a large Persian army, not 300 Persian troops, and it was not against the Athenian navy.

Answer:

B. at the Battle of Thermopylae.