GMAT Sentence Correction (SC) | One legacy of Madison Avenues recent campaign to appeal to

One legacy of Madison Avenue’s recent campaign to appeal to people fifty years old and overis the realization that as a person ages, their concerns change aswell.
(A) the realization that as a person ages, their (Pronoun Error)
(B) the realization that as people age,their
(C) to realize that when a person ages, his or her (Legacy is not to do something, it issomething)
(D) to realize that when people age, their (Legacy is not to do something, it issomething)
(E) realizing that as people age, their