Correct option is A
Option (a) is correctly spelt word.
Correct spelling: “Irreverence” – Lack of respect for people or things that are generally taken seriously.
(अनादर या असम्मान)
Example: His irreverence towards sacred traditions offended many.
Note: "Irreverence" comes from “reverence” (गंभीर श्रद्धा), and adding the prefix “ir-” makes it negative.