After that tiresome long journey, he felt drowsy.

The correct answer is A. sluggish.

After a long journey, people often feel tired and sleepy. This is because they have been using a lot of energy and their bodies need time to rest and recover. Sluggish is a word that describes someone who is tired and slow-moving. It is the best word to describe the feeling of

The other options are not as accurate. B. irritable means easily annoyed or angry. C. energetic means full of energy and enthusiasm. D. dizzy means feeling lightheaded and unsteady. These words do not accurately describe the feeling of being drowsy after a long journey.