A New Species of Mammal Is Discovered Deep in the Antarctic

Multiple Choice

A new species of mammal is discovered deep in the Antarctic. This mammal contains an organ that does not seem to be homologous to any other known organ. Upon examination, it appears that this organ is responsible for secreting hormones necessary for regulating subcutaneous fat levels to regulate body temperature. To which system does this new organ most likely belong?

A) digestive system
B) integumentary system
C) immune system
D) endocrine system
E) nervous system