All of the following are major internal sources of new-product ideas, except which one?

• A. Picking the brains of company executives, scientists, engineers and salespeople is a good way to generate ideas.
• B. Intrapreneurial programs that encourage employees to think and develop new-product ideas is a good way to generate ideas.
• C. Some companies employ creative approaches, including both "method and madness" in helping them to generate new product ideas.
• D. Good ideas come from watching and listening to customers.