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 light of the above statements, choose the most appropriate answer from the options given below:

Statement I: The 4f (lanthanides) and 5f (actinides) series are placed separately at the bottom of the Periodic table to preserve the principle of classification and to maintain the structure of the table. This is true.

Statement II: s-block elements (alkali and alkaline earth metals) are highly reactive and are not found in pure (free) form in nature. They always occur in combined forms (as compounds). This is false.

Statement I is true but Statement II is false. The answer corresponds to Option (3).