Why do the other fishermen race toward Kino?

a
Juana was signaling to them that Kino needed help.
b
They heard Kino scream.
c
Kino just caught an enormous fish.

c

Kino just caught an enormous fish.

c. Kino just caught an enormous fish.

The answer is c) Kino just caught an enormous fish. The other fishermen race toward Kino because they see the potential fortune that can come from catching such a valuable fish. The large fish represents an opportunity for wealth and prosperity, so the other fishermen want to be a part of the action and potentially benefit from it as well.