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 'D'. (Ignore the errors of punctuation, if any)
The passing marks (a)/ in Economics is thirly three (b)/ but he has secured (c)/ just twenty-nine (d)/ No error

Answer

a

Explanation

Instead of "passing marks" you should use "pass mark", because "passing marks" is not correct.