Find the domain of the function ( f(x) = 9/x² + 8x + 12 ). What is the domain of ( f )?
a) ( x (-fty, -6) ∪ (-6, -2) ∪ (-2, fty) )
b) ( x (-fty, -2) ∪ (-2, -6) ∪ (-6, fty) )
c) ( x (-fty, -6) ∪ (-6, -2] ∪ [-2, fty) )
d) ( x (-fty, -6] ∪ [-6, -2) ∪ (-2, fty) )