Finally, thank you very very much! I'm really so happy to have the answer to my question. Whoo... Therefore, I'm going to remember this 'not working and till at last' situation to prevent any certain problems in the future. Addition, I understand why I made my own mistake that's confusing you all. It was the question with the correct answer that's not actually the 'right answer,' but it is. So that's why you get confusing, because according to one of the test practice's instructions say "Which...NOT...," which I didn't added it in the first place and that's why. I'm apologizing about that for what I have done is my careless mistakely. Well, everyone made a mistake. No one is perfect, of course.