Which of the following changes would be likely to make terrestrial life on this planet impossible?

Read the following statements carefully and select the correct ones.
$I.$ $UV$ rays are essential for the production as well as degradation of ozone gas.
$II.$ Ozone present in the ionosphere acts as a shield absorbing $UV$ radiation coming from the sun.
$III.$ One-fourth of the incoming solar radiation is reflected by the atmospheric gases and clouds,and only half of the incoming solar radiation falls on the earth's surface,heating it. Of this,only a small portion is reflected back.

Loss of forest,urbanization,and increasing pollution are all due to:

Choose the incorrect statement.

Assertion : Methane,a component of greenhouse gases,contributes about $20$ percent to global warming.
Reason : The introduction of multi-point fuel injection engines in automobiles has decreased methane content in the exhausts.

The Government of India passed the Environment (Protection) Act in the year $............$.