Suppose the initial position of an object is zero, the starting velocity is 3 m/s and the final velocity was 10 m/s. The object moves with constant acceleration. Which part of a velocity vs. time graph can be used to calculate the displacement of the object? A. the area of the rectangle under the line B. the area of the rectangle above the line C. the area of the rectangle plus the area of the triangle under the line D. the area of the rectangle plus the area of the triangle above the line