The correct option is D D
Let’s examine the sentence: “He has been ill since five years.” The preposition ‘since’ is used for a point of time and not period of time. As ‘five years’ given in the sentence is a period of time, it would be indicated by the preposition ‘for.’ So the correct sentence would be, “He has been ill for five years.” So, the error is in Part D of the sentence. Hence, Option D is the correct answer.