In the following sentence, some parts have errors and some are correct. Find out which part has an error and mark it as your answer. if there is no error mark 'option E'

You get water if you mix hydrogen and oxygen. (A)/ This is one of the earliest reactions known to mankind. (B)/ Now we are trying to separate hydrogen (C)/ from water in order to use it as a fuel. (D)/ No error (E)