Concept:An antonym is a word opposite in meaning to the given word.
Explanation:The word "irritates" means to annoy or provoke.
So we need a word that means the opposite, that is, to please or make happy.
Among the options, "delight" means to give great pleasure.
"Concern" means to worry, "invigorate" means to energize, and "bother" means to annoy.
Therefore, "delight" is the correct opposite.
Answer:A. delight