What implicit message could most clearly be inferred from the National Geographic video?
O A. Flu vaccines are only partly effective.
B. Sick passengers should fly in first class.
O C. Scientists will soon find a cure for the flu.
O D. People should wash their hands regularly.

Read the passage. when mother’s fever persisted for a week, father summoned our family doctor. dr. blakemore applied leeches to mother’s skin in hopes of reducing the amount of blood in her body. despite the doctor’s efforts, she languished in bed for three more days before her appetite returned and she requested a thin broth. our dear cook, mrs. davis, prepared the broth and delivered it to my mother directly, eager to ease her discomfort. what can readers infer about the time period of the passage?