Which Approach Is Most Likely to Enhance Children's Ability to Classify

Which approach is most likely to enhance children's ability to classify objects?

A) Tell the children to find all of the red ones.
B) Provide the materials that could be classified for the children to use on their own during free play.
C) Explain in detail what attributes are and how they vary, and quiz children about their comprehension of this instruction.
D) Ask children to sort materials and then tell you why they put certain things together.