Read each of the following sentences to find out whether there is an error of errors in any underlined part(s). if you feel that there is no error in the sentence, choose (E) to signify ‘None of the above’.

Correct option is D

Man should be replaced with Men and
The correct form of the verb after "has" in this context is "understood," not "understand." Therefore, the corrected sentence is: "Men has scarcely understood the importance of clean water."