Siegler's Research on Rule-Based Problem Solving Using the Balance-Scale Task

Siegler's research on rule-based problem solving using the balance-scale task suggests that

A) preshoolers are unable to use rules to solve problems.
B) when there is low memory demand and instructions are repeated, preschoolers can solve a problem with two dimensions.
C) even after they are given repeated instructions, preschoolers have difficulty solving a problem with two dimensions.
D) most preschoolers can solve a problem with two dimensions without any instructions.