In India, natural gas is found in the that are major producers of natural gas.

Why is $\mathrm{CNG}$ preferred as a fuel?

Read the following passage and answer the question.
Ali noticed that thick, black smoke was coming out from his school bus. He met the transport in-charge and convinced him to get the bus checked for harmful gases emission.

Suggest an environment-friendly fuel for this bus.

Give reason for the following:

CNG is a better fuel for automobiles.