<prompt> A man presented with bilateral crepitations in the base of the lungs and signs of pneumonitis with a history of exposure to pigeon feces. Which of the following is true about this condition?Diagnosis can be made on the basis of historyCT scan is investigation of choiceChest X-ray will reveal characteristic changesIt is type I hypersensitivity reaction  <response>: Ans. a. Diagnosis can be made on the basis of history 