What Would Be the Concentration of Hydronium Ions in a Solution

What would be the concentration of hydronium ions in a solution that had a pH = -3? Why would such a solution be impossible to prepare?

A) Concentration of H³O⁺ = 3 M. It is impossible because it is hard to measure such a small amount of hydronium ions accurately.
B) Concentration of H³O⁺ = 30 M. It is impossible because pH can not be negative.
C) Concentration of H³O⁺ = 10³⁰ M. It is impossible because any container used to hold the acid would immediately corrode.
D) Concentration of H³O⁺ = 10³ M. It is impossible because only so much acid can dissolve in water before the solution becomes saturated.