[单选题]
The potential difference between the terminalsrn:m3e)w oo 40+0cfo f ccigd8 o4banwc k+po e6(1tqp )f a battery, when no current flows to an external circ+ tbwc )a1pe(q6nokp4 uit, is referred to as the
A. battery emf
B. terminal voltage
C. battery power
D. battery rating