A: Marilyn Monroe
Marilyn Monroe has brains (A=B). Marilyn Monroe is beautiful (A=C). Marilyn Monroe is beautiful with brains (A=B+C).
XineAnn has brains (D=B). XineAnn is beautiful(D=C). XineAnn is beautiful with brains (D=B+C).
To sum it up: A=B+C=D hence A=D
I knew it!
Sharply observed by MBMC and inspired by the eternal etheoreal