You must get x by itself and eliminate the negative of the x. By doing that, you can get x<-1/6
If you do the elimination process, here it is.
- A : Too small
+ B : I think so
- C : I little too big
- D : Way too big
For this case we have the following data:


So that the figure can be a rectangle, its diagonals must be equal, that is, 
In this way we have:

Clearing x we have:


Thus, x must be equal to 10 so that the figure is a rectangle.
Answer:

Option A