Which of the following solutions is acidic?
A) [H₃O+] = 7.0 x 10⁻⁷ M
B) [H₃O+] = 1.5 x 10⁻¹⁰ М
C) [H₃O+] <7.0 x 10⁻⁷ M
D) [H₃O+] > 7.0 x 10⁻⁷ M
E) [H₃O+] = 1.0 x 10⁻¹⁴ M