[单选题]
The energy acquired by a particle carrying a/*g5o(3n8ojqajipz ei n-4r b charge equal to that oex;owk dd/yn :98m5p/a gyqs,n the electron as a result of moving through a potential difference of on,5/x odpn;y9egmaw d: 8skqy/e volt is referred to as
A. a joule.
B. an electron-volt.
C. a proton-volt.
D. a coulomb.
