[单选题]
The primary of a transformer halo(eatildzj zx) u(+ bo4q o)b42zw01s 100 turns and its 8bibf 7-fgw8 hsecondary has 200 turns. If the power input to the primab8-7hbf g iw8fry is 100 W, we can expect the power output of the secondary to be (neglecting frictional losses)
A. 50 W.
B. 100 W.
C. 200 W.
D. none of the given answers
