[单选题]
A lever is 5.0 m long. Txk44pnal(eq5:gym2 k e6d6jrwbd6),h k tmi 8he distance from the fulcrum to the weight to be lifted is 1.0 m. If a 3000 N rock is to be lifted, how much force must be exerted on the levij,r8e hb)m6td kd 66wer?
A. $600 \; N$
B. $750 \; N$
C. $3000 \; N$
D. $12000 \; N$