Which function has an inverse that is also a function? a. {(–4, 3), (–2, 7), (–1, 0), (4, –3), (11, –7)} b. {(–4, 6), (–2, 2), (–1, 6), (4, 2), (11, 2)} c. {(–4, 5), (–2, 9), (–1, 8), (4, 8), (11, 4)} d. {(–4, 4), (–2, –1), (–1, 0), (4, 1), (11, 1)}