The presence of the rh factor on the red blood cell tells you whether or not you have the rh
a. antigen
b. antibody
c. agglutinin
d. pathogen

A. antigen

Explanation:

An antigen is a protein that is present over the surface of the red blood cells. The type of antigen present over the surface of the red blood cell determine the blood type ( A, B, AB, O). The Rh factor is an antigen which is an inherited protein that can be found over the surface of the red blood cells. If an individual posses Rh antigen in the blood that will exhibit the Rh positive blood type. The one which does not posses the Rh antigen in the blood will be consider as Rh negative blood type.  

a motor homunculus represents a map of brain areas dedicated to motor processing for different anatomical divisions of the body.

homunculus represents the importance of various parts of your body as seen by your brain. as a result, they take up a lot of brain space. although the cortical homunculus is a curiosity, penfield's work in mapping the brain's relationship to the body was invaluable.

he is very short, and he can only reach halfway up on the elevator buttons. but on a rainy day, he has his umbrella with him, and he uses it to poke the button at the top.