What is the domain of the discrete finite function F(x)?

G(x) = {(–2, 1), (–1, 3), (1, 4), (7, 3), (2, 5)}

A{–2, –1, 1, 2, 7}

B{–2, 1, 3, 4, 5, 7}

C{1, 2, 7}

D{1, 3, 4, 5}