[单选题]
If the velocity versus tifr5i(l ow cs;8me 1pk oyqo 3agxs c0f:b3qc+iar0. i*(eya17 x tgraph of an object is a horizontal line, the object isxcoy . 0a3+aig7 tx3yf ik:pose1c*a (b1qq0r
A. moving with constant non-zero speed.
B. moving with constant non-zero acceleration.
C. at rest.
D. moving with infinite speed.