横向弛豫是指90°射频脉冲结束后，宏观磁化矢量：Transverse relaxation is defined as （ ） after the end of 90 ° RF pulse:
选项：

A:Mxy由小变大的过程The process of Mxy increasing to the maximum
B:Mxy由大变为零过程The process of Mxy decreasing from the maximum to zero
C:Mz由大变小的过程The process of Mz decreasing from the maximum to zero
D:Mz由小变大的过程The process of Mz increasing to the maximum