1 - propanol and 2 - propanol can be best distinguished by:

Fehling’s solution or Fehling Test is used to distinguish between aldehydes and ketones.

Aldehydes give a red precipitate with Fehling solution, whereas ketones do not react at all with the Fehling solution.

The only way to distinguish 1-propanol and 2-propanol using Fehling Solution is to convert then into aldehydes and ketones.

This can be done by oxidizing them with copper and then treating with Fehling solution.

The correct option is C: Oxidation by heating copper followed by reaction with Fehling's solutions.