Read each sentence to find out whether there is any error in any underlined part and indicate your response in the Answer Sheet against the corresponding letter i.e., (a) or (b) or (c). If you find no error, your response should be indicated as (d).

The error is in third part. The adjective hard has two different adverbs, and they express opposite meanings. The adverb hard is used to modify a verb and means that the action is being done very intensely. The adverb hardly is used to modify a verb and means that the action is not being done very intensely. So there the correct usage will be ‘working hard’.