John Smith Works Outdoors in the Winter at a Ski

John Smith works outdoors in the winter at a ski resort. His thyroid hormone levels are

A) lower in the winter to conserve body heat.
B) higher in the winter to increase body temperature.
C) lowered in the summer after his job to decrease body temperature.
D) increased in the summer after his job to increase body temperature.
E) unaffected by his job.