Over the past few years, Walmart Stores have replaced most of their hourly-paid cashiers with automated self-check-out machinery. What effect does this change have on Walmart's fixed costs and operating leverage? O O O O Fixed Costs Decrease Fixed Costs Increase Operating Leverage Increase Operating Leverage No effect Fixed Costs Increase Fixed Costs No effect Fixed Costs Increase Operating Leverage Increase Operating Leverage No effect Operating Leverage Decrease