Growing trees does not disturb the balance of gases in the air.

Explanation:
Growing trees actually helps maintain the balance of gases in the air. Trees play a vital role in the process of photosynthesis, where they absorb carbon dioxide from the air and release oxygen. This helps to replenish the oxygen content in the atmosphere and reduce the amount of carbon dioxide, a greenhouse gas, in the air.

Here is a detailed explanation of each option:

a) Cutting down trees and forests:
Cutting down trees and forests has a negative impact on the balance of gases in the air. Trees absorb carbon dioxide and release oxygen through photosynthesis. When trees are cut down, the carbon dioxide they had absorbed is released back into the atmosphere, contributing to an increase in greenhouse gases. Additionally, the reduced number of trees means less oxygen is being produced, further disturbing the balance of gases in the air.

b) Releasing polluting gases into the air:
Releasing polluting gases into the air, such as carbon dioxide, methane, and sulfur dioxide, greatly disturbs the balance of gases. These gases are released from various human activities, including burning fossil fuels, industrial processes, and vehicle emissions. They contribute to the greenhouse effect and global warming, leading to climate change and air pollution.

c) Growing trees:
Growing trees does not disturb the balance of gases in the air. As mentioned earlier, trees absorb carbon dioxide and release oxygen through photosynthesis. This helps to maintain the balance of gases in the air by reducing the amount of carbon dioxide and increasing the oxygen content.

d) Releasing smoke from vehicles:
Releasing smoke from vehicles, especially those that burn fossil fuels, contributes to air pollution and disturbs the balance of gases. Vehicle emissions release carbon monoxide, nitrogen oxides, and particulate matter, which are harmful to human health and the environment. These pollutants can lead to smog formation and respiratory problems.

In conclusion, growing trees is the only option that does not disturb the balance of gases in the air. It actually helps in maintaining the balance by absorbing carbon dioxide and releasing oxygen through photosynthesis.