Which of the relations given by the following sets of ordered pairs is a function?
A. {(2,-8),(6,4),(-3,9),(2,0),(-5,3)}
B. {(-2,5),(7,5),(-4,0),(3,1),(0,-6)}
C. {(1,-3),(1,-1),(1,1),(1,3),(1,5)}
D. {(1,2),(2,3),(3,4),(2,1),(1,0)}
B. {(-2,5),(7,5),(-4,0),(3,1),(0,-6)}
This set is a function because no two pairs have the same first element.