Answer: D. Test marketing
Step-by-step explanation:
Test Marketing is a stage in the New Product Development process where the product is tested in the real world or the Field Laboratory as it is otherwise known. Here the consumers are given a sample of the products and their responses are recorded without them knowing they are part of a test making their reactions as genuine as can be.
This stage helps the company more accurately ascertain how the new product will fare in the real world thereby giving them a chance to fix whatever needs fixing.