[单选题]
A 4.0-kg object is attached to a spring of sp55 jgvdyxle: eo1n(hz7 :u c(pring constant 10 N/ *ci5d)psb,p am. The object is displ5p *piba)cd,saced by 5.1 cm from the equilibrium position and let go. What is the frequency of vibration?
A. $0.25 \; Hz$
B. $0.50 \; Hz$
C. $1.0 \; Hz$
D. $2.0 \; Hz$
