Question

what is the meaning of the word discern as used in the passage? as the sun began to set, the island castaway was barely able to discern a ship on the horizon. did that mean that someone onboard the ship might be able to notice him, too? he jumped to his feet and frantically waved his arms, yelling, \over here! over here!\ to detect to search for to reach

Explanation:

In the passage, the castaway "barely able to discern a ship" implies he could just barely detect it. "To search for" would mean actively looking, and "to reach" is unrelated. So "to detect" matches the context of perceiving the ship.

Answer:

to detect