Which sentence best shows the central idea of the excerpt?

O "Elizabethans do not understand infection and

contagion as we do."

O "It is not that they are completely ignorant as to how

illnesses spread—physicians believe they know

perfectly wellit is rather that their understanding is

very different from ours."

O "The principal ideas underpinning most Elizabethan

medical thinking come from Galen, who lived in the

second century A. D."

O "If there is too much choler in your body, you will grow

choleric; too much blood and you will be sanguine, too

much phlegm and you will be phlegmatic; and too

much black bile makes you melancholic."