The correct option is C If it is not a holiday, then today is not diwali.
For any conditional staements p→q
Converse statement is q→p
Inverse statement is ∼p→∼q
Contrapositive statement is ∼q→∼p
Performing any two action always result in third one.
So, in this case
p= today is diwali,
q= it is a holiday
Inverse of Converse statement is contrapositive statement \∼q→∼p
⇒ If it is not a holiday, then today is not diwali.