challenge: How is Aurintricarboxylic acid typically prepared?
  
  A. By the hydrolysis of salicylic acid with sulfuric acid
  B. Through the condensation of formaldehyde with salicylic acid in the presence of nitrite-containing sulfuric acid
  C. By the reaction of salicylic acid with nitric acid
  D. By the oxidation of formaldehyde with nitric acid
  Answer: 