A Small Person with a Surface Area of About $1.0 \mathrm{~m}^{2}$

Multiple Choice

A small person with a surface area of about $1.0 \mathrm{~m}^{2}$ must (by the Stefan-Boltzmann law) radiate energy at a rate that would require eating 11,000 food calories a day if they are naked in a vacuum in deep space. Which do you think is the most important reason that someone sitting in a normal room requires less than 2000 calories a day?

A) Wearing clothes reduces the radiation loss.
B) Wearing clothes reduces heat loss due to convection.
C) A person has an emissivity $\varepsilon$ much smaller than 1 .
D) The person absorbs radiation from the room.
E) The surrounding air insulates the person.
F) Something else (specify) .