Option 1 states that carbon monoxide absorbs heat and contributes to the warming of the atmosphere. This statement is incorrect. Carbon monoxide is not known to absorb heat in the Earth’s atmosphere.

Option 2 states that oxygen absorbs heat and contributes to the warming of the atmosphere. This statement is incorrect. Oxygen is a major component of the Earth’s atmosphere, but it does not have the property of absorbing heat.

Option 3 states that soot absorbs heat and contributes to the warming of the atmosphere. This statement is correct. Soot is a type of particulate matter that can absorb sunlight and heat up the atmosphere.

Option 4 states that water vapor absorbs heat and contributes to the warming of the atmosphere. This statement is correct. Water vapor is a greenhouse gas that absorbs heat radiated from the Earth’s surface and helps to keep the planet warm.

Therefore, the correct answer is option 3, as soot and water vapor are the only substances listed that have the property of absorbing heat and contributing to the warming of the atmosphere.