What does this metaphor mean?

My brother's stomach is a bottomless pit.

Question 2 options:

He has a stomach problem.

He can eat a lot.

He works in construction.

The correct option is: He can eat a lot.

This metaphor is used to convey the idea that the person referred to has an incredibly large appetite and is capable of eating a significant amount of food. Comparing the person's stomach to a bottomless pit suggests that no matter how much food is consumed, their hunger is never satisfied, as a bottomless pit cannot be filled.