The correct answer is C.
Hope this helps!!
Actually, yes, this is true. Let's look at some examples with the word "all" to see if it agrees with verbs in singular or in plural:
All is lost
All is well
All is arranged already.
All of it is nice
This shows us that "all" agrees with verbs in singular form: the correct answer is a) True.
I think it is A. Teenagers are an enjoyable and necessary part of our society.
“It is awfully hard work doing nothing”
