The correct answer is B

Explanation

Figures in a Coordinate Plane
The figure provides all the information you need to answer the question.

What Is the Question Asking?
You are asked to figure out the area of a triangle that is defined by the points in a coordinate plane.

What Do You Know?
The triangle in the figure is a right triangle with the right angle at the lower left.

Because it is a right triangle, its base and height are the two sides that form the right angle.

The area of a triangle is (1 over 2) times b times h.

The base of the triangle extends from point (0 comma 0) to point (5 comma 0). So it is 5 units long.

The height of the triangle extends from point (0 comma 0) to point (0 comma 3). So it is 3 units long.

Area = (1 over 2) times b times h

(1 over 2) times 3 times 5

(1 over 2) times 15

equals 7.5