B vs D

@Minerva, Happy to help. Let's take a look at (B) and (D). (B) says, "A beginning chess player should use pattern recognition techniques when deciding what move to make." This is tricky, as the writers are attempting to get us to think that chess beginners should use the same techniques as experts. The problem with this is that it assumes that the usefulness of the pattern recognition techniques is transferrable to beginners. This is almost certainly false, as the expert has played in far more chess matches, so her pattern recognition techniques are likely to be of greater use to her than for a beginner. Thus, we can get rid of (B). (D) says, "In playing chess, an expert player relies crucially on his or her memory." The definition of "crucially" is "with decisive or vital importance." The stimulus tells us that expert players primarily use pattern recognition techniques. While "crucially" is a strong word, we know that experts have to use their memory in order to use the pattern recognition techniques, and we know these experts mainly use these techniques, so this wording, although strong, is supported by our stimulus. Does this make sense? Let us know if you have any more questions!

This was very helpful Ravi, thanks!

@Minerva, you're welcome! I'm happy it helped!