Factors that may trigger vasodilation or vasoconstriction include all of the following EXCEPT: (an explanation would help immensely if possible)

A- the metabolic rate determined by activity will influence the regulation of temperature
B - some substances such as alcohol and nicotine interfere with temperature regulating mechanisms
C- the chemical activity of the small intestine plays a major role in the temperature homeostasis
D - the brain, in response to a change in BP, influences temperature regulation directly