[单选题]
A stationary electron0ysiw6i qh; wnkj 2 q-rh+9c+w5w.(wu- x5cdyhqcp5 t is accelerated through a potential difference of 500 V. What is the velocity of the w-u w xh.(ctqp5y5cd5 electron afterward?
A. $1.3 \times 10^{6} \; m/s$
B. $2.6 \times 10^{6} \; m/s$
C. $1.3 \times 10^{7} \; m/s$
D. $2.6 \times 10^{7} \; m/s$
