古时有“守株待兔”的寓言，设兔子的头部受到大小为自身重力2倍的打击力时即可致死，如果兔子与树桩的作用时间为0.2s，兔子与树桩相撞的过程可视为匀减速运动．则被撞死的兔子其奔跑速度可能是（g=10m/s²）（　　）

A．1.5m/s

B．2.5m/s

C．3.5m/s

D．4.5m/s

Rare species in the world, ______ by hundreds every year, must be jointly preserved by all countries, or humans will encounter ecological disaster in the near future.