Which of the following is the best example of the product development stage?

a

Breaking down the feasibility of such a system based on the cost of development.

b

Delivering multiple versions of different phones to influencers for beta testing.

c

The engineering of the quad$-$camera feature.

d

Ranking the concept of high$-$quality camera versus other potential differentiators.

e

Research revealing that customers are limited by existing smartphone cameras.