Final answer:
Lens coating is most likely to be considered a separate performance obligation related to the purchase of prescription eyeglasses because it provides a distinct, additional function to the glasses.
Step-by-step explanation:
The student's question pertains to identifying which option would be treated as a separate performance obligation when purchasing prescription eyeglasses. A performance obligation in this context means a promise to transfer a distinct good or service to the customer.
Of the options provided, lens coating is most likely to be considered a separate performance obligation because it represents an additional service that can distinctly enhance the functionality of prescription lenses, such as by reducing glare or improving scratch resistance. Frame color is generally considered a customization of the same performance obligation as the frame itself. A case and cleaning solution are typically seen as ancillary items that do not represent separate performance obligations, as they are not distinct goods or services that could be purchased separately in the deal.