The correct answer is:
The interpretation the best explains how the passage demonstrates the use of metaphor in the story is:
A. The author illustrates the idea of starvation with the glass of milk.
Writers use metaphor to create a range of meanings, so, the more we read the better we can interpret the meaning in a certain narrative text. By interpreting that figurative language we can discover our own understanding, this is why a text could have a different meaning to different readers. The task of understanding differs depending on the context; even literary critics spend long periods of time trying to decipher what metaphors mean.
In this case in particular I have chosen option A, because that is to me the best interpretation. When a person suffers from starvation usually feels a burning pain which may be relieved by eating, and milk is supposed to provide relief. So, our character was facing a threat of hunger and feeling such pain that with just a sip of milk (which could have been a bite of bread) felt that the pain began to disappear.