Write the domain in interval notation f(x) = log₄(x²-16).
a) (-[infinity], -4) ∪ (-2, 2) ∪ (4, [infinity])
b) (-[infinity], -4] ∪ [-2, 2] ∪ [4, [infinity])
c) (-[infinity], -4) ∪ (-2, 2] ∪ (4, [infinity])
d) (-[infinity], -4] ∪ (-2, 2] ∪ [4, [infinity])