Final answer:
In the context of the PDSA model, the example of 'Do' is implementing the new skin care protocol on all medicine units.
Step-by-step explanation:
The nurses on a medical unit, having noticed an increase in pressure ulcers among patients, decide to employ the Plan-Do-Study-Act (PDSA) model for a quality improvement project. The "Do" phase of this model involves the implementation of the change or test being studied. Therefore, among the given options, an example of "Do" would be 'Implement the new skin care protocol on all medicine units.' This action directly applies the new protocol in a practical setting, which can then be assessed for effectiveness in subsequent phases of the PDSA cycle.