A dc power supply has no-load voltage of 30v,and a full-load voltage of 25v at full-load current of 1A.Its output resistance & load regulation ,respectively are_____________?
A. 5 Ω & 20 %
B. 25 Ω & 20 %
C. 5 Ω & 16.7 %
D. 25 Ω & 16.7 %