Which odorant is commonly used in propane to provide it with a smell?

The correct answer is that ethyl mercaptan is the odorant commonly used in propane to give it a distinct smell, which is essential for safety. Ethyl mercaptan is a highly effective odorant due to its strong and recognizable scent, often described as resembling rotten eggs or skunks. This makes it easier for individuals to detect even small leaks of propane, which is odorless in its pure form. The implementation of this odorant is a significant safety feature for preventing accidents and facilitating prompt responses in the event of a leak.

While the other options mention different types of mercaptans, they are either not used for propane or are less effective odorants in terms of safety requirements. Ethyl mercaptan's specific properties make it the preferred choice for ensuring that propane can be easily detected, thereby protecting individuals from the dangers associated with gas leaks.