[单选题]
A force moves an object inmtkow vm(g*1+ the dir 3jnnh3 6 sfa*qd6nj,jection of the force. The graph in Fig. 6-1 shows the force versus the object's position. Find the work done when the object m*3nsajn jfqjhnd66 3 ,oves from 0 to 6.0 m.
A. $20 \; J$
B. $40 \; J$
C. $60 \; J$
D. $80 \; J$
