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

a) Truly innovative companies seldom rely on customers and the general public for ideas.

b) The purpose of idea generation is to reduce the number of ideas to the least possible number.

c) Truly innovative companies rely exclusively on a single source for new-product ideas.

d) Truly innovative companies develop extensive innovation networks that capture ideas and inspiration from various sources.

e) Customers are the least important sources of new-product ideas.