PLEASE HELP WILL GIVE 15 POINTS AND GOOD RATINGS

Determine whether each relation is a function. Explain.

{(1, 12), (4, 18), (7, 22), (10, 28)}

a.
yes; Each element of the domain is paired with exactly one element of the range.

b.
yes; Each element of the range is paired with exactly one element of the range.

c.
no; Some values of the domain are paired with more than one value of the range.

d.
no; Some values of the range are paired with more than one value of the domain.