B. on the rocks
on the rocks depicts a place/setting which would be a prepositional phrase just like in or behind, in front etc.
hope this helps! brainliest answer would make my night!
Explanation:
Gregor's father emphasizes how well Gregor prioritizes the important things in life like work and supporting his family. This reinforces the theme regarding isolation because it stated that Gregor doesn't do anything outside of work.
i hope this help