What substance is added to natural gas to help detect leaks?

Answer: B — Mercaptan

The substance added to natural gas to help detect leaks is mercaptan. Natural gas, in its pure form, is odorless and colorless, making it difficult to detect any leaks merely by sight or smell. Mercaptan is a compound that imparts a strong, distinctive odor, often described as resembling rotten eggs. This characteristic smell makes it much easier for individuals to notice natural gas leaks quickly, enhancing safety measures. By incorporating mercaptan into natural gas, residential and commercial users can take prompt action in case of a leak, which is crucial for preventing potential accidents or explosions. The choice of mercaptan specifically is due to its effectiveness and safety profile, making it the standard odorant used in the industry.