Based on the excerpt, readers can conclude that Odysseus (the speaker)

Excerpt: They scrambled to their places by the rowlocks

and all in line dipped oars in the gray sea.

But soon an offshore breeze blew to our liking—

a canvas-bellying breeze, a lusty shipmate sent

by the singing nymph with sunbright hair.

So we made fast the braces, and we rested,

letting the wind and steersman work the ship.

From the excerpt above, The answer is B. Odysseus credits the singing nymph for the favorable wind

Explanation:

Odysseus meets Circe, and after Odysseus leaves Circle and he was been favoured with her advice for his journey ahead. The scene that this excerpt hails from was encountered, Odysseus is seen happy and feels blessed by the nymph "with sunbright hair" He realizes he was blessed as the wind is favoring him and allowing him to sail with ease. Odysseus gives that credit to the nymph for blessing him with such a good fortune.

a.) it provides a clue to solve the mystery.