[单选题]
Starting from rest, a proton falls through a potential differejrac -wyz0-o5 (m qcpxe,ob0dx,ggz6) s7v ,t nce of 1200 V. What speed does it acqugs)bp(v7 o0mg cz,,x,de6 tqx ire?
A. $1.2 \times 10^{5} \; m/s$
B. $2.4 \times 10^{5} \; m/s$
C. $3.6 \times 10^{5} \; m/s$
D. $4.8 \times 10^{5} \; m/s$
