Metaphor is one of the many figures of speech in which it uses implied comparison between two or more things that are not related but with specific similarities. Here are examples:
The rejection I received is another door for a great opportunity ahead.
She is the glasses of his eye frame.
<span>She has bouncy balls of emotions just by seeing him.</span>
I believe the answer is 3
<span>a.to help the reader visualize the thorough precautions that were in place</span>
Lennie could not survive on his own which why George is with him