The gas which has a rotten egg smell is:A. hydrogen peroxideB. chlorineC. hydrogen sulphideD. carbon dioxide

The gas that has a rotten egg smell is C. hydrogen sulfide.

Explanation:
Hydrogen sulfide (H₂S) is a colorless gas known for its characteristic foul odor, often described as similar to that of rotten eggs. It is produced naturally during the decomposition of organic matter and is also found in some volcanic gases and natural gas.

Hydrogen peroxide (H₂O₂) is a chemical compound used primarily as a disinfectant and bleaching agent. It has a slightly sharp odor but does not smell like rotten eggs.

Chlorine (Cl₂) is a greenish-yellow gas with a strong, pungent odor, often associated with bleach. It does not have a rotten egg smell.

Carbon dioxide (CO₂) is an odorless gas produced by respiration and combustion. It does not have any specific smell.

In summary, the correct answer is C. hydrogen sulfide due to its distinct rotten egg smell.