In the question stem, we are asked to chose a type of perceptual experience that affect judgment.
A) recall cues : thats having extra clues to remember something. Nothing to do with perceptual experience
C) feature detector : ability to detect certain type of stimuli , like the shape of objects. This won't affect our judgment.
D) practice effect : thats when our performance increases when we practice more and more. Again, Nothing to do with perceptual experience
Now we have B left. Context effects : this is the right answer choice, The context within which we perceive something affects our judgement , for example in figure C in the passage, we make associations , based on the context, to make a new shape (a closed triangle)
hope this helps