Tammy Foley Had Always Had a Fascination with Firearms and Physics

Tammy Foley had always had a fascination with firearms and physics. So when he learned of the difficulty of capturing a near-perfect round for ballistics matching to weapons used in crimes, he thought he might develop a system for testing bullets and firearms. While considering the possibility of developing such a product, Foley realized his major problem was in finding a medium that would diffuse the energy of a bullet as it leaves the muzzle of a firearm. He spent three years testing almost 300 different variations and combinations of synthetic and natural materials before developing a method that worked. He named his company Ballistics Research. At a demonstration for FBI agents, Foley fired a variety of different kinds of firearms into his ballistics testing system and retrieved each one in the condition in which it left the muzzle. Forensics experts at the demonstration expressed disbelief as they watched the various trials. The ballistic testing units are priced at $12,000, and very few law enforcement agencies can afford to spend that much.
-As Foley tested the various synthetic and natural materials to see how well they diffused the force of a bullet leaving a muzzle, he would have been in which stage of the new-product development process?

A) business analysis
B) idea generation
C) idea screening
D) market test
E) prototype development