Consider the relation S={(−2,4),(−1,1),(0,0),(−2,5)} from R to R. Which statement about S is correct?
(a) S is a function because all outputs are distinct numbers.
(b) S is not a function because the input −2 corresponds to two different outputs.
(c) S is a function with domain {−2,−1,0}.
(d) S is a function because an input may have more than one output, but each output comes from only one input.