Let's read the text again...
My grandfather the fisherman always told me that the best way to communicate with fish is to drop them a line.
There are three phrases that help us to understand the pun in the text: The grandfather is a fisherman, it means his job is to catch fish, by communicate he means to make the fish come closer, and by drop them a line he means the fishing rod thread.
Taking the above into account the correct answers are:
A.“communicate” and “drop them a line”
B.The pun plays on a phrase that means both to send a note and to attempt to catch a fish.
