Question: How do they control for annotation artificats?
Answer:  we use several of the MCQA baseline models first introduced in BIBREF0
Alternative answer: Choice-Only model, which is a variant of the well-known hypothesis-only baseline, Choice-to-choice model, tries to single out a given answer choice relative to other choices, Question-to-choice model, in contrast, uses the contextual representations for each question and individual choice and an attention model Att model to get a score