This question asks who can’t go directly in front of the vase. To answer this, ask yourself what rules involve V.
That’s rules 3 and 4. But 4 is most useful. We saw V must go in one of these two orders:

We can see that H can’t be directly in front of V: T separates the two variables.
So A is CORRECT.

Hello, I am reaching out wondering why the lamp couldn’t be in front of the vase. Based off of the diagrams you have posted, I cannot seem to wrap my head around how L is any different from H. Would you please be able to help clarify this? Thank you!