I think it's pretty cool.

  Question: Which nucleobase is not present in the DNA, 
  (a) thymine
  (b) uracil
  (c) adenine
  (d) guanine
  (e) cytosine

  Aristo's Answer: (b) uracil

  Confidence: 53.92%

  Justification Sentence: In DNA, the uracil nucleobase is replaced by thymine.