Answer:
[H3O+] = 1.0 x 10-10
Explanation:
A basic solution is any solution whose pH is above 7.0.
If we carefully calculate the pH of each of the species listed among the options, we will discover that it is only [H3O+] = 1.0 x 10-10 that has a pH of 10.0. This pH corresponds to a basic solution. Hence the solution having [H3O+] = 1.0 x 10-10 is a basic solution.