The correct option is B Acid: 0 - 7 and Base: 7 - 14
The strength of acidic and basic substances is measured with respect to pH scale. The standard value of an acid on a pH scale is between 0 - 7 while the substances that are basic have the value ranging between 7 - 14. For the strong acids like HCl, the value of pH is around 0 to 1. For weaker base like ammonia, the pH is about 11.