Given below are two statements:
Statement $I$: Cleistogamous flowers are invariably autogamous.
Statement $II$: Cleistogamy is disadvantageous as there is no chance for cross-pollination.
In the light of the above statements,choose the correct answer from the options given below:

• A
  Both Statement $I$ and Statement $II$ are incorrect.
• B
  Statement $I$ is correct but Statement $II$ is incorrect.
• C
  Statement $I$ is incorrect but Statement $II$ is correct.
• D
  Both Statement $I$ and Statement $II$ are correct.