Which sentence shows correct capitalization?

A. Although president Roosevelt was by no means the only president to have taken an interest in social justice issues, Roosevelt was one of the few to have made it a central focus of his presidency.
B. Sir Henry the Wonder dog, my basset hound, had snuck out from under the back fence again to join the dogs next door.
C. We heard Governor Smith say that, although she did not want to weigh into such a controversial issue, other Governors had urged her to share her thoughts.
D. Of all my aunts, it was Aunt Marge who really encouraged my interest in painting.