[单选题]
Starting from rest, a proton falls through a potential dix*4b2xfp lbk 5ffnz65n(y;2lskk lw 0jrerence of 1200 V. What speednjy6l0krls2 zw ;n( k5 does it acquire?
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. $4.8 \times 10^{5} \; m/s$
