The electric potential a distance r away from a cylinder can be calculated by dividing a charge q into ( )

A、theworkdoneonthemagneticfieldasachargeqmovesfromapointonthecylindertoapointoutsidethecylinder.
B、theworkdoneonthemagneticfieldasachargeqmovesfromapointonthecylindertoapointinsidethecylinder.
C、theworkdoneontheelectricfieldasachargeqmovesfromapointonthecylindertoapointoutsidethecylinder.
D、theworkdoneontheelectricfieldasachargeqmovesfromapointonthecylindertoapointinsidethecylinder.
E、theforceonachargeqasitmovesfromapointonthecylindertoapointinsidethecylinder.