I can see that it has been over a month and they did not answer your question, but let me see if I can take a shot at it. I believe the reason answer (B) incorrect is because the author never gives us anything indicating that he/she would gravitate towards thinking that it should be used ONLY during opening statements, as (B) would suggest - it is simply too narrow of an answer.
Answer choice (D) is the best answer because the author explicitly states that, "Although no empirical research has directly tested the effectiveness of stealing thunder... the technique is, in fact effective,..." (line 11-15). After that phrase, the rest of the passage is dedicated to providing experimental research and psychological explanations to why jurors (or people in general) think the way they do due to stealing thunder. Hence, "can be psychologically explained" (answer choice B) is also true.
I hope that helps
Shunheon December 24, 2019
Hi all, just wanted to say that @mmahareeq215's reasoning for why (B) is incorrect is spot-on! The reasoning for why (D) is the best is also correct. Thanks for helping clear things up!
