[单选题]
A mass on a spring undergoes gb;fk+r3s-a hSHM. When the mass/wy ,zsk6xxnrd,s,wx 5 bs3z;d i ,gr jn*7e0d passes through the equilibrium position, its i z5 w xs63;n/jdrdw,e s,by,kd0*i ,rxg xsz7nnstantaneous velocity
A. is maximum.
B. is less than maximum, but not zero.
C. is zero.
D. cannot be determined from the information given.