[单选题]
98.21: The diagram to the right depicts iron f k .sggdp94ohdc3 z*)qilings sprinkled a5dgoyc,wcbd( p -ml2,round three permanent magnets. Pole R is the same -gp ,c 2wom d5(dybc,las poles
A. poles T and Y
B. poles T and Z
C. poles X and Y
D. poles X and Z
E. poles S, T, and Z
