Nthe code onkey(draw_9,"r"), what will happen when a lowercase "r" is typed on the keyboard?

In the code onkey(draw_9, "r"),  when a lowercase "r" is typed on the keyboard the draw_9 function will be called. The ONKEY function returns the key value that precipitated the signaling of the KEY condition during an input/output operation to a file that is being accessed by key. 

It should be b i believe