Yana, an 82-year-old, active great-grandmother, recently was admitted to a local nursing home. Upon visiting his mother, Sergei is excited to report on the grandkids and great-grandkids. However, Sergei is surprised at his mother's despondence and lack of interest in hearing about the children she loves so much. Yana's attitude seems to reflect __________.(A) activity theory(B) selective optimization(C) institutionalism(D) biological maladjustment