Final answer:
The correct answer is option c. Tiresias warns Odysseus not to harm the cattle of the Sun during his voyage, which is a crucial point in Homer's epic The Odyssey.
Step-by-step explanation:
The warning given by Tiresias to Odysseus pertains to his journey as detailed in Homer's epic, The Odyssey. Upon visiting the underworld, Odysseus encounters Tiresias, the blind prophet, who foretells the further challenges he will face on his return to Ithaca.
Among the predictions, Tiresias warns Odysseus not to harm the cattle of the Sun (owned by the Sun god, Helios), which would bring grave misfortune upon him and his crew. Unfortunately, his men do not heed this warning, leading to disastrous consequences.