Geraflex, a new exercise program designed to strengthen muscle in the elderly, is offered year-round, and a typical class contains between five and ten members, most of whom already suffer from age-related muscle loss. Classes are generally larger from April through October; from November through March, class sizes tend to be smaller. The variation in class size can probably be explained by a decrease in mobility among the elderly during the winter months.
Which of the following, if true, provides the strongest support for the explanation offered?
(A) From April to October, more Geraflex classes are offered than from November to March.
(B) Geraflex class sizes vary dramatically in size from year to year.
(C) Many elderly people travel to warmer climates during the winter months.
(D) An effective muscle strengthening program requires much more extensive stretching in the colder winter months.
(E) During the winter months in many areas, roads and sidewalks are more dangerous, so the elderly are less likely to leave their homes.