The correct answer is b. The Boy Scout used camphor to soothe the burns he got from the campfire.
Camphor is a compound that can be used topically as a soothing agent for minor aches and pains, and it was historically used in some medicinal formulations. However, it's important to note that camphor should be used with caution and it is not recommended for use in infants or young children.
So while option b uses the word correctly in context, option c is inappropriate because camphor should not be given to babies for treating colds. Therefore, option b is the best choice.