A solution is said to be acidic when it's value on the $pH$ scale is between the range:

The correct option is C 0-7
The range of possible values for the ratio in an aqueous acid solution is 0 to 1.
Because the $H^{+}$ ion concentration must be between 0 to 1.
Because for the pH value of the solution , the $H^{+}$ ion concentration must fall in this range, to determine it's acidic nature.