Given below are two statements about sewage. Based on them,select the correct option given below.
Statement $I$: The sediment in the settling tank is called floc.
Statement $II$: Sewage is first passed in the grit chamber,then it is screened.

• 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.