Among magazines that target audiences by age, the most dramatic recent success has come from those aimed . tweens. b. young adults. c. children. d. thirty- to forty-year olds. e. adults over fifty.

Among magazines that target audiences by age, the most dramatic recent success has come from those aimed at adults over fifty.

Explanation:

Adults over fifty years were the targeted audience for reading magazines. According to science, an adult who practices reading for more than thirty minutes gains a longer span of life. It psychologically results in cognitive engagement in adults and it also increase concentration and the feeling of empathizing with others.  

Their social perception becomes positive and emotional intelligence is heightened. It is also a mean to keep the adult cognitively active and it is very beneficial for the people who are aged above fifty.  

they all focused on themes about the inevitability of death.