Step 1: Explaining Plato’s divided line.
Plato divides knowledge into four levels: Eikasia, Pistis, Dianoia, and Noesis, ranging from illusion to pure intellectual insight.
Step 2: Locating mathematical knowledge.
Mathematics belongs to Dianoia because it involves abstract reasoning based on hypotheses rather than direct perception or ultimate forms.
Step 3: Distinguishing from Noesis.
Noesis is reserved for direct understanding of the Forms themselves, not for mathematical reasoning.
Step 4: Conclusion.
Therefore, Plato places mathematical objects in the realm of Dianoia.
Final Answer: (A) Dianoia [Thought]