An operations task performed at Hard Rock Café is __________.

An operations task performed at Hard Rock Café involves preparing employee schedules because it directly relates to the management and organization of daily operations within the restaurant. Effective scheduling is crucial for ensuring that there are enough staff members available to meet customer demand while also managing labor costs. This task incorporates elements like peak dining times, employee availability, and roles required for smooth service.

The other choices represent functions that are more closely aligned with marketing, finance, or design rather than operations. Advertising changes in the restaurant menu pertains to promotional efforts, calculating profit and loss is a financial analysis task, and designing the restaurant layout focuses on the physical arrangement of the space, which is typically handled by design or project management teams rather than standard operational tasks. Hence, preparing employee schedules is the most relevant operational task among the options provided.