In the sentence, which word-segment could mean 'fishing in troubled waters'?
Knowing the past bitter experience with the rival firm, Ms. Vijaya cautiously approaches the subtle negotiation, already being aware of the fact that she is fishing in troubled waters.
To be a fish in troubled waters is to be involved in a very difficult or delicate situation, which could cause you problems. Therefore, Optionn C best captures the meaning of the idiom.