To determine the conductivity of the acidic solutions from least conductive to most conductive, we can use the pH values provided. Generally, the lower the pH, the higher the concentration of hydrogen ions (H⁺) in the solution, which typically means greater conductivity.
Given the pH values:
- HA: 5.6 (higher pH -> less acidic)
- HB: 3.9 (lower pH -> more acidic)
- HC: 4.7 (intermediate pH)
From least to most acidic (and thus least to most conductive):
- HA (pH 5.6)
- HC (pH 4.7)
- HB (pH 3.9)
Thus, the order from least conductive to most conductive is:
HA, HC, HB.
None of the provided options seem to directly match that response. However, if the order is strictly needed based on the exact choices listed and we consider that HC is less conductive than HB but more conductive than HA, the final, correct ordering according to the responses would be:
- HA, HC, HB
So the best choice from the list given is: HA, HC, HB.