What Is the H₃O⁺ Concentration in 0 $\circ$ C? (K_w = 1

What is the H₃O⁺ concentration in 0.0047 M NaOH(aq) at 25 ^$\circ$ C? (K_w = 1.01 $\times$ 10^-14)

A) 2.1 $\times$ 10^-12 M
B) 4.7 $\times$ 10^-3 M
C) 1.0 $\times$ 10^-14 M
D) 1.0 $\times$ 10^-7 M
E) 4.7 $\times$ 10^-17 M