Which of the following gas is majorly responsible for the Greenhouse effect?

Cabondioxide

The correct answer is option 2. Carbon dioxide.

Out of the choices you listed, Carbon Dioxide \((CO_2)\) is the major contributor to the greenhouse effect.

Here's a breakdown of the gasses and their contribution:

Carbon Dioxide \((CO_2)\): This is the most significant greenhouse gas due to human activities. It traps heat efficiently and persists in the atmosphere for a long time.

Methane \((CH_4)\):  Methane is a potent greenhouse gas, but its atmospheric concentration is lower than \(CO_2\). However, it traps more heat per molecule than \(CO_2\).

Oxygen \((O_2)\): Oxygen is not a greenhouse gas. It plays a vital role in respiration but doesn't trap heat like greenhouse gases.

While methane and other gases contribute to the greenhouse effect, Carbon Dioxide is the dominant factor due to its high concentration and extended atmospheric presence.