[单选题]
What work is required to stretch a s f8ack216 , vm l14w1jzjenxyhpring of spring constant 40 N/m from x = 0v2kg 6ej0c )5evvgn* n.20 m to 0.25 m? (Asjgk0 n25nvg*)vcee 6vsume the unstretched position is at x = 0.)
A. $0.45 \; J$
B. $0.80 \; J$
C. $1.3 \; J$
D. $0.050 \; J$
