Answer: b. thick atmosphere
The atmosphere of planet Venus is hot and thick. It is consist of gases like carbon dioxide, and clouds of sulfuric acid, which are chiefly responsible for making the planet hot.The Venus atmosphere traps the energy from the sunlight. The sunlight adds up to the overall thermal energy of the planet. The atmosphere is composed of reducing gases like carbon dioxide, nitrogen, and very less amount comprises with carbon monoxide, argon, sulfur dioxide, and water vapor. These gases makes the atmosphere of Venus thick and hot.
Hence, Venus is known for its thick atmosphere.