Answer:
C. they develop a research design
Step-by-step explanation:
After they define the problem, they need a way to conduct a research in order to collect information that can help them addressing the problems.
Research design is the way they create structure and integrate different factors in the study. The design is made to ensure that the information the obtain with the study will be relevant to the problems that they intend to solve.
In business, research design can implemented by collecting customers with similar characteristic as a subject group, asking them question to know about preference, asking them to try a certain product prototype, etc.