[单选题]
If the position versus time graph of no odn8:mm ee:d c7,+9ruc az*an object is ew* o6h.z-)e- g:chn2qovdmu a horizontal line, the object i:6gdve-o-hho m. uz2)w c*neq s
A. moving with constant non-zero speed.
B. moving with constant non-zero acceleration.
C. at rest.
D. moving with infinite speed.
