Bertrand Russell differentiates between:
1. Knowledge by acquaintance: Direct experience or perception of objects.
2. Knowledge by description: Knowledge of things not directly experienced, derived through inference.
Russell asserts:
- Description involves inference and the use of concepts, making (A) and (D) incorrect.
- Physical objects and other people's minds are often known by description, contradicting (B).
- Description is ultimately reducible to acquaintance (C), as descriptions depend on direct experiences.
Thus, the correct answer is (B), (C).