Read the passage and answer the below question:At last the bomb was made. The site chosen for the test explosion was the desert region two hundred miles from Los Alamos. Ten seconds before Zero hour, a green flare warned the spectators to keep down. Then came the blinding flash. The whole area was suddenly brighter than the brightest daylight, and the bomb was a ball of fire. Then came thetremendous roar and the heavy pressure wave, which knocked down two men outside the control center. And then came the cloud - the mushroom cloud, all the colours of the rainbow, ironically beautify, surging up to over 40,000 feet-over 10,000 feet higher than Everest.The writer uses the phraseironically beautifulto describe the mushroom cloud because.

• A. he knew that mushroom would not have the colour of rainbow
• B. he is aware of the sinister nature of the explosion that took place
• C. he believes that something that is higher than the Mt. Everest cannot be described asbeautiful
• D. he wants to convey his sympathy for the two men who were knocked down