[单选题]
The potential difference between the terminals of a battery, whenh;w8fq ltzelm tg80 *j9f sgb8+sb4 k; curre 8 l v;e(uhkt5 bik-+:qmp p-isn(2owbnt flows to an external circuit, is referrempilw:pth u ;bqb (5(ove8--k +knis2 d to as the
A. battery emf
B. terminal voltage
C. battery power
D. battery rating
