[单选题]
A ball of mass 0.10 kg ildl mt32ag 8qbf+ p5u*s dropped from a height of 12 m. Itcl )y3zx-7o4mwv7j(nulnw+ rz 8gs e)s momentum when it strikes (gwo4n mc3 )r7+yu )jwlvzl7-zex8ns the ground is
A. 1.5 kgm/s.
B. 1.8 kgm/s.
C. 2.4 kgm/s.
D. 4.8 kgm/s.
