Water Ionizes According to the Following Reaction Which Requires Approximately $\rightarrow$

Water ionizes according to the following reaction which requires approximately 1200 kJ/mol of energy

H₂O(l) + h v $\rightarrow$ H₂O⁺ + e^-
In what portion of the electromagnetic spectrum are you likely to find the radiation that carries just enough energy to be dangerous to life because it can ionize the water that is so important to living organisms?

A) Radio/TV waves, $\lambda$ $\approx$ 10 - 0.1 m
B) Microwaves, $\lambda$ $\approx$ 0.01 - 10^-4 m
C) Ultraviolet, $\lambda$ $\approx$ 10^-7 - 10^-9 m
D) X-rays, $\lambda$ $\approx$ 10^-10 - 10^-12 m
E) $\gamma$ -rays, $\lambda$ $\approx$ 10^-12 - 10^-14 m