Answer:
D.The length is 3 times the width.
Explanation:
We are given that
Area of rectangle =

We have to find that coefficient 3 what represents in given terms.
From given figure we can see that
Width of rectangle=x
Length of rectangle=3x
Area of rectangle=

Area of rectangle=

To find that coefficient 3 what represents we will compare between width and length of given rectangle.
Length of rectangle =

It means length of rectangle is 3 times the width of rectangle.
Option D is true.