Which of these sentences would best express the main idea of a presentation about george washington's life?

a) george washington was a very tall man, especially for the time period in which he lived.
b) george washington and his troops stayed over the winter in valley forge to prepare for war with the british.
eliminate
c) george washington was the first president of the united states and one of the greatest leaders in our country's history.
d) during the farewell address he gave before leaving office, president george washington warned against political parties.