How Did Dr

How did Dr. H.T. Hammel determine that it was the hypothalamus in dogs which was sensing their temperature?

A) He kept their heads at a different temperature than their bodies and they reacted only according to the temperature of their heads.
B) He kept the hypothalamus at a different temperature than their external environment, and they reacted only according to the temperature of the hypothalamus.
C) The dogs did not react at all to changes to the external environment unless their head temperature was changed, also.
D) The dogs would only pant when their skin temperature was increased.
E) The dogs would not shiver when just the hypothalamus was cooled.