Final answer:
Thetis seeks out Hephaestus to replace her son Achilles' armor, knowing well that it cannot prevent his fated death. Hephaestus, the god of forge and craftsmanship, had created Achilles' original special armor. Option A is the correct answer.
Step-by-step explanation:
In Homer's Iliad, Thetis, the sea nymph and mother of Achilles, after foreseeing her son's death, seeks to ensure that he is well-equipped for his destiny in battle. She goes to Hephaestus, the famed blacksmith of the gods and god of the forge, to request a new set of armor for Achilles, acknowledging that even divinely crafted armor cannot thwart the fates.
Hephaestus is renowned in the pantheon of Greek gods for his skill in metalwork and craftsmanship, which is why Thetis turns to him for assistance. Hephaestus had previously crafted Achilles' original armor, already known for its special and divine properties. Despite the new armor's inability to change Achilles' predestined demise, it symbolizes his heroism and the high regard in which he is held by both gods and mortals.
The answer to the question 'Who does Thetis ask to replace Achilles' armor even if it won't save him from fated death?' is: a. Hephaestus.