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).
I was standing at the bus stop waiting for him since eight o'clock.
I was standing
at the bus stop
waiting for him
since eight o'clock.
No error
Correct answer is A
I had been standing