[单选题]
The appearance of the gre-6 c 8n9rqc c3bl(* jo;pszn6/ vxk5dyby-vasat ra +x4ekl ;34qs * sgzgr/xec1adnge of brightness among stars is due to
A. the differences in the amount of light different stars emit.
B. the differences in the distances of stars from us.
C. both of the given answers
D. none of the given answers
