Q.

Assertion: Carbon forms ionic compounds.
Reason: It is because of its valency of 4.

1 Assertion and reason both are true and reason is the correct explanation of assertion.  
2 Assertion and reason both are true but reason is not the correct explanation of assertion.  
3 Assertion is true, but reason is false.  
4 Assertion is false, but reason is true.  

Ans.

(4)

Carbon forms covalent compounds because of its valency of 4, it is tetravalent in nature due to which it can share its 4 electrons easily.