Concept:Mathematics is hierarchical, meaning advanced concepts are built upon simpler, foundational ideas.
Explanation:Multiplication is simply repeated addition, so it directly builds on the concept of addition.
Number sense (understanding what numbers mean) is a prerequisite for learning addition and subtraction.
Statement (b) is false because multiplication and addition are interdependent.
Statement (c) is false because mathematics should be assessed through both formative and summative methods.
Thus, the pair that correctly explains the hierarchical nature is (a) and (d).
Answer:B. (a) and (d)