help can someone please explain why H isn't in 2 for this question?

Admin Note: Edited title. For LG questions, please use the format: "PT#.S#.Q# (G#) - brief description of question."

I've been studying this site for over a year and I consistently get only half right on LR. There is no specific question type that I have an issue with but it's all up and down the board. Each test is a new group of question types wrong, so right when I think I have something mastered I don't. What can I do to get about 18 right instead of 12 right consistently?