Step 1: Option Analysis.
- Idealism (A), exemplified by F.H. Bradley's philosophy, aligns with IV. - Rationalism (B), linked to D. Hume's emphasis on reason, corresponds to II. - Empiricism (C), which posits knowledge derived from sensory experience, is associated with B. Spinoza, matching with III. - Pragmatism (D), founded by C.S. Peirce, corresponds to I.
Step 2: Conclusion. Option 2 is the correct choice.
Final Answer: \[ \boxed{\text{The correct answer is 2. A - I, B - II, C - III, D - IV.}} \]