Which of the following statements about tuberculosis (TB) testing is accurate?
a) A positive skin test reaction indicates exposure to TB but is not a diagnosis of acute TB.
b) Frequent serial x-rays are required to monitor progression of TB lesions in the lungs when TB skin test is positive.
c) The result of TB skin test is not affected by a history of Bacillus Calmetto Guerin vaccination.
d) A positive skin test reaction means that the area of erythema was greater than 10 mm in diameter at 48 hours.