[单选题]
A force moves an obje7,jvpjo 7rlt6 ct in the direction of v sp/ g58ymtd:vim5ew4v u6*xthe force. The graph in Fig. 6-1 shows the force versus the object's position. Find the work done when the object moves from 0 to4devtsim8/5yxmu pvgv 6w :5* 6.0 m.
A. $20 \; J$
B. $40 \; J$
C. $60 \; J$
D. $80 \; J$
