From the Perspective of Cognitive Psychology, Why Should We Not

From the perspective of cognitive psychology, why should we not expect students to solve complex problems in their heads?

A) The capacity for complex problem solving does not emerge until late adolescence.
B) Asking students to solve complex problems promotes rote memorization rather than meaningful learning.
C) Students' working memories can hold only a few pieces of information at a time.
D) By trying to solve complex problems in their heads, students are likely to "unlearn" some of the information stored in their long-term memories.