[单选题]
Ignoring air resistancd pzlc)9 o7q0z +oirtsp;5w e6(kps5ke, the horizontal component of axck0kur * z t1(o3/plqso:n+pg 4tbr 2 projectile's acceleration *r3l/qkcoz pst +x0pbu1r2 go4t:( nk
A. is zero.
B. remains a non-zero constant.
C. continuously increases.
D. continuously decreases.
