Identify the correct direct speech form of the following sentence:
My teacher told me that I am not working hard.

Option A is incorrect as it cannot be told to me. It should be either told me to said to me.

Options B and C doesn't give the same meaning as the given sentence. In option B, it doesn't refer you to anyone in particular. Therefore, the meaning doesn't remain the same. And in option C, the teacher is not telling to the narrator, and hence would not be correct. 

Option D is the correct direct speech form.

Answer is option D.