[单选题]
If the velocity versus time grapnez36v ha qpn28ah:2mso8o c8h ozc7zg(,c f io4pa v6r8;u,w dab8k 8mqf an object is a horizontal line, the object is8 cvmz7rkf;adi pg, b 8z,wc(oq4ua86
A. moving with constant non-zero speed.
B. moving with constant non-zero acceleration.
C. at rest.
D. moving with infinite speed.
