Answer:
B
Step-by-step explanation:
Mars atmosphere contains mainly carbon iv oxide, but the greenhouse effect as subdued as there is so little CO2 overall.
Venus as a planet contains 96.5% of carbon iv oxide. it doesn't contain water which can trap the CO2 as we have on earth where the oceans are able to trap the CO2 present and subdue the greenhouse effect. This inability to trap CO2 in Venus prevents infrared rays from escaping and with the fact the Venus is closer to the sun than earth and mars, its surface it extremely hot.