Hey there!
Here is your answer:
The proper answer to this question is option C"the best alternative value ".
Reason:
A opportunity cost is a person making a tough decision between many other decisions. For example a movie, a football game, or laser tag. You will have to think of the outcomes of each decision and how would they affect you for example think of what is more fun to you.
Therefore the answer is option C.
If you need anymore help feel free to ask me!
Hope this helps!
~Nonportrit