Question

Determine which sets of ordered pairs represent functions from A to B? Explain your reasoning A={x,y,z,w} and B={1,2,3,4,5}. if you have any insight please help me

answer choices:
a. {(y,1),(x,2),(z,2),(w,3)}
b. {(z,2),(x,1),(w,5),(z,4)}
c. {(w,1),(z,3),(y,2)}