[单选题]
If the velocity versus time graph ooon* 7*z 6zejcf an object is a hord-, dlwwzg0u 26bdk.+tc-byn izontal line, the object is-d0,bt+- w.ud2 bklgcwz 6dyn
A. moving with constant non-zero speed.
B. moving with constant non-zero acceleration.
C. at rest.
D. moving with infinite speed.
