Only One of the Following Teaching Practices Is Consistent with What

Only one of the following teaching practices is consistent with what we know about working memory. Which one?

A) Mr. Adamson tells his students that,with practice,they will be able to do complicated long division problems in their heads.
B) Ms. Borelli tells her students that they should try to focus on main ideas rather than try to remember every detail.
C) Ms. Constas suggests that students in her Russian class listen to Russian audiotapes while they sleep.
D) Mr. Dominowski urges his students to put information for tomorrow's test in their "short-term memories."