'X' is most inert element and 'Y' is most reactive element in the long form of the periodic table. 'X' and 'Y' are respectively

We know that most inert elements are inert gases i.e. from He to Rn

Since He is the most inert element, we know that F is the most reactive element due to its small size and high electronegativity.

Hence, X is He and Y is F.

Then, Option(b) is the answer.