[单选题]
A convex spherical mirror has a f* cc/ pkr2:cub6qz-sj ocal length of -20 v/p n gcf c(v1p5i1vm1cm. An object is placed 10 cm in front of the mirror on the mirror's axis.gcvvm1c p 115p/fv( in Where is the image located?
A. 20 cm behind the mirror
B. 20 cm in front of the mirror
C. 6.7 cm behind the mirror
D. 6.7 cm in front of the mirror