Which idea-generating technique are you using when you write the pros of an issue in one column and the cons in another column?
A brainstorming
B. mapping
C listing
D. outlining

when you write the pros of an issue in one column and the cons in another column you are using C. Listing as an idea generating techniques.

Explanation:

Idea generating techniques are basically the tools that a person uses for their mental exercise to better generate ideas that then are deployed in the problem solving that they have at hand.

This particular problem shows the person listing out the pros and cons of a certain thing and this is a tell tale sign of the technique called listing wherein different aspects of a  topic are listed out one by one by the person attempting the exercise to generate more aides about it.

the rhyme scheme is abab cdcd efef gg.

cockroaches and rats often are a symbol for things that are disgusting or vile. though i don't know which play you are talking about, i hope this !