As you said above, the word "bob" means fencing and you want to know how this can have a double meaning related to homophobes.
This is what I see the 2 meanings as:
1. fencing, as in taking out your fencing sword
2. take out your penis, as penis would be another word for sword in plays/books such as the one you're reading - this would be relating to gays if the convo was btwn 2 men
I think the correct answer is A