For a better understanding of the solution given here please find the attached file which has the diagram of the kite EFGH.
As can be seen from the diagram,

Also, it is given that

We are required to find the
.
To proceed we know that a kite is a quadrilateral and in a quadrilateral the sum of the interior angles is 360 degrees. Thus, we will get:

Plugging in the given values we get:

This will give:

Therefore, Option B is the correct option.