Answer:
Option B. 36
Explanation:
we know that
A relationship between two variables, x, and y, represent an inverse variation if it can be expressed in the form 
 or
 or 

The graph of the figure represent an inverse variation
so
In this problem
Constant=Height*Width
Take any point in the graph
example -----> the point (4,9)
Constant=4*9=36