Answer: (D) Suppliers
Step-by-step explanation:
According to the given question, the organization using the various types of internal sources as it helps in developing the various types of new products ideas in the market.
The supplier is one of the common internal source in an organization as it helps the employees for encourage them for developing various types of new ideas and concepts.
The organization basically developing various types of new ideas by the formal research process and also through the development. Therefore, Option (D) is correct answer.