Answer the following question given this paragraph: 

The strength of bases is measured on a scale called the pH scale, which ranges from 0 to 14. On this scale, a pH value of 7 indicates a neutral solution, and a pH value greater than 7 indicates a basic solution. The higher the pH value is, the stronger the base. The strongest bases, such as drain cleaner, have a pH value close to 14.


Q: The strength of bases is measured on what scale?

 Choices:

- acid test

- litmus test

- pneumatic scale

- ph scale

A:
ph scale
