Given below are two statements:
Statement $I$: An allotrope of oxygen is an important intermediate in the formation of reducing smog.
Statement $II$: Gases such as oxides of nitrogen and sulphur present in the troposphere contribute to the formation of photochemical smog.
In the light of the above statements,choose the correct answer from the options given below:

• A
  Both Statement $I$ and Statement $II$ are false.
• B
  Statement $I$ is true but Statement $II$ is false.
• C
  Both Statement $I$ and Statement $II$ are true.
• D
  Statement $I$ is false but Statement $II$ is true.