Read the sentence below to find out whether there is any grammatical error in it. The error, if any, will be in one part of the sentence. Choose the option with that part as your answer. If there is no error, choose 'D' as your answer. (Ignore the errors of punctuation, if any).
When we consider all the factors, which are many, the number of school dropouts are quite disturbing.
When we consider all the factors, which are many,
the number of school dropouts
are quite disturbing.
No error.
Correct answer is C
is quite disturbing.