This essay will discuss both sides of this approach.
It is not necessary to indicate how the essay will be written. You already made that clear in the prompt restatement. What you should have done was presented a topic basis for the advantage and disadvantage that you plan to further develop in the later paragraphs. Do not forget that you need to provide your opinion, at least based on the writing instruction, in general form. In this case, it is not an opinion you are being asked to give. You just have to give an idea of how you will be discussing the topic. That way you will meet the TA writer's opinion section requirement.
Remember to edit your work before submission to avoid unnecessary deductions. In this case, you did not capitalize a certain first word of a paragraph, which will result in a minimal GRA deduction in terms of writing rules, plus additional writing deductions for incorrect word usage and the like.