The shear force at the center of a simply supported beam with a gradually varying load from zero at both ends to w per meter at the center, is
A
Zero
B
$$\frac{{{\text{w}}l}}{4}$$
C
$$\frac{{{\text{w}}l}}{2}$$
D
$$\frac{{{\text{w}}{l^2}}}{2}$$
Correct Answer: Zero