Given below are two statements:
Statement $I$ : The $4f$ and $5f$-series of elements are placed separately in the Periodic table to preserve the principle of classification.
Statement $II$ : $S$-block elements can be found in pure form in nature.
In the light of the above statements,choose the most appropriate answer from the options given below :

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