Read each sentence to find out whether there is any grammatical error in it. The error, if any will be in one part of the sentence. The letter of that part is the answer. If there is no error, the answer is 'E'. (Ignore the errors of punctuation, if any).
He has been undergoing the special training course which each of the employees is required to.
He has been undergoing
the special training course
which each of the employees
is required to.
No error
Correct answer is D
is required to undergo