下面是有关燕麦实验的示意图。图中所示燕麦胚芽鞘的某些部位纵向插入了云母片。请分析图中a～f的琼脂块中，生长素含量正确的是

A．a<b, c="d," e<f	B．a<b, c="d," c="f"
C．a<b, c<d, c="f"	D．a>b, c="d," e<f