[单选题]
A spherical mirror on which reflectoi 4o/yhrjd)4 ion takes place on the inner sust8:ko7nokj0mym +hm43a- evrface of the sphere is referred-yntojmshk v emm+ ao:7k8340 to as a
A. convex mirror.
B. concave mirror.
C. plane mirror.
D. double-sided mirror.
