Describe the typical phases of failure rate over a product's life (the bathtub curve).

• A. Early-life (infant) failures with decreasing hazard, a middle 'useful life' with roughly constant hazard, and wear-out failures with increasing hazard.
• B. Early-life (infant) failures with increasing hazard, a middle 'useful life' with roughly constant hazard, and wear-out failures with decreasing hazard.
• C. Hazard remains constant throughout life.
• D. Early-life failures with constant hazard, middle-life decreasing hazard, wear-out with constant hazard.

Answer: (A)