The gas responsible for the greenhouse effect on Venus is:

Carbon dioxide (CO2)
Oxygen (O2)
Ozone (O3)
Nitrogen (N2) E. Water vapor (H2O)

The correct answer is: A. Carbon dioxide (CO2).

Carbon dioxide is the most important greenhouse gas on Venus. It is responsible for about 96% of the greenhouse effect on Venus. The other 4% is caused by water vapor, clouds, and other trace gases.

The greenhouse effect is a natural process that helps to keep the Earth warm. Greenhouse gases trap heat in the atmosphere, which prevents it from escaping into space. This is what makes the Earth habitable for life.

However, human activities are increasing the amount of greenhouse gases in the atmosphere. This is causing the greenhouse effect to become stronger, which is leading to global warming.

Carbon dioxide is the most important greenhouse gas that humans are emitting. It is released into the atmosphere when we burn fossil fuels, such as coal, oil, and natural gas.

Water vapor is also a greenhouse gas, but it is not as important as carbon dioxide. Water vapor is a natural part of the atmosphere, and it helps to regulate the Earth’s temperature. However, when the Earth’s temperature increases, more water vapor is released into the atmosphere. This can cause a feedback loop, where the Earth’s temperature continues to increase.

Ozone is a greenhouse gas, but it is not as important as carbon dioxide or water vapor. Ozone is created when oxygen molecules are split by ultraviolet radiation from the sun. Ozone is found in the stratosphere, which is the layer of the atmosphere above the troposphere. The ozone layer helps to protect the Earth from harmful ultraviolet radiation.

Nitrogen is the most abundant gas in the atmosphere, but it is not a greenhouse gas. Nitrogen does not trap heat in the atmosphere.

In conclusion, the gas responsible for the greenhouse effect on Venus is carbon dioxide.