Question

asphyxiation is a hazard posed by compressed natural gas (cng) vehicles and can be detected when you notice this smell. options: spoiled milk, cinnamon, burning, rotten eggs

Explanation:

Compressed Natural Gas (CNG) has an added odorant for safety, and the odor of CNG leaks is often similar to rotten eggs (due to the added mercaptans or similar odorants to detect leaks). Spoiled milk has a sour smell, burning is a different type of hazard/smell, and cinnamon is not associated with CNG leak detection. So the correct smell indicating a CNG leak (and asphyxiation hazard) is rotten eggs.

Answer:

Rotten eggs (the option with "Rotten eggs" text)