Answer:
The correct answer is option D "opportunistic"
Step-by-step 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.