Consider the relation R={(1,2),(2,3),(1,4)} defined from {1,2} to {2,3,4}. Which of the following correctly states whether R is a function and why?
a) R is a function because every element of the codomain appears at most once.
b) R is a function because each element of the domain has at least one image in the codomain.
c) R is not a function because the input 1 is associated with two different outputs.
d) R is not a function because the output 3 is used only once.