Which of the following statements is true of the idea generation stage in the new product development process?
选项：

A: The purpose of idea generation is to reduce the number of ideas to the least possible number.
B: Truly innovative companies rely exclusively on a single source for new product ideas.
C: Customers are the least important sources of new product ideas.
D: Truly innovative companies develop extensive innovation networks that capture ideas and inspiration from every possible source.
E: Truly innovative companies seldom rely on customers and the general public for ideas.