[单选题]
The net work done in :7wx9f+kti z8b mog, kmoving n(11 3f29 hyrf bmupepan electron from point A, where the potential is -50 V, to point B, where the potential is +5 nh193y fp(up e2bfmr10 V, is
A. $+1.6 \times 10^{-17} \; J$.
B. $-1.6 \times 10^{-17} \; J$.
C. zero.
D. none of the given answers
