English Grammar find the error in given sentence

it covers /(a)the loophole in our /(b) defense mechanism./(c)no error/(d) - it covers / (a) the loophole in our / (b) defense mechanism./(c)no error / (d) - find the error in given sentence English Grammar in hindi,  Spot the error  question answers in hindi pdf   questions in hindi, Know About English Grammar online test English Grammar notes in hindi quiz book