Based on its structure, which word most likely means "someone who takes advantage of circumstances”?

credulous
disdainful
proactive
opportunistic

The correct answer is option D "opportunistic"

Explanation:

The word "opportunistic" means taking advantages of immediate opportunities usually when they are not planned.

The word "proactive" on the other hand means taking action in order to produce a change instead of  waiting for something to occur.

Disdainfull means showing no respect and credulous means to believe in something that you are told without analyzing if it is true or not.

the choice that is not a technique that you should use to come up with ideas for the topic of a research project is, writing about academic subjects that are not interesting to you. this does not belong to the techniques to come up with ideas because having no interest in a certain topic will lose your drive to come up with better ideas. it gives no room for improvement and acquiring of new ideas and information. 

explanation: