Which statement best describes the area of Triangle ABC shown below?
A. It is twice the area of a rectangle of length 4 units and width 5 units.
B. It is one-half the area of a rectangle of length 4 units and width 5 units.
C. It is twice the area of a square of side length 5 units.
D. It is one-half the area of a square of side length 5 units.