Of the following persons, which one would you expect to have the densest bones?+ a. an elderly woman

Of the following persons, which one
would you expect to have the densest bones?+

 a. an elderly woman whose favorite
pastime is knitting b. a 16-year-old female who swims regularly c. a
33-year-old male who loves to drink milk and plays basketball regularly d. a
50-year-old male workaholic with a desk job