1. The problem asks: What defines a controllable cost? 2. A controllable cost is one that a manager can influence or change through decisions and actions. 3. Let's analyze the options: - A. "Is incurred by past decisions" refers to costs already committed, which are typically uncontrollable now. - B. "Can be influenced by a manager" matches the definition of controllable costs. - C. "Is allocated" means costs assigned to a department or product, not necessarily controllable. - D. "Is sunk" refers to costs that cannot be recovered or changed, thus uncontrollable. 4. Therefore, the correct answer is B. Final answer: **B. Can be influenced by a manager**