[单选题]
Estimate the speed of an alpha p*svmf9zz6: ,trd6xy1nka; o l article that has accelerated fr c;j s0o.wxx,vt, j.kiwok j0:om rest in a uniform electric field oxojwjwk., it 0 .s0x,;vjk:cE=50 $^{−1}$ over a distance of 2.0m.
A. $0.5\times10^4\,ms^{−1}$
B. $5.0\times10^4\,ms^{−1}$
C. $0.5\times10^5\,ms^{−1}$
D. $0.5\times10^9\,ms^{−1}$