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C is corrent. The requirement is to identify the activity that is excluded from research and development costs. Research is defined as planned search or critical investigation aimed at the discovery of new knowledge, and development is defined as the translation of research findings or other knowledge into a plan or design for a new product or process. C is corrent because quality control during commercial production is not part of the research and development process.
A is incorrect because it represents a research and development cost.
A is incorrect because it represents a research and development cost.
D is incorrect because it represents a research and development cost.