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}