Brainstorming, "a group problem$-$solving technique that involves the spontaneous contribution of ideas from all members of the group" $($

Merriam$-$Webster.com, $2019)$ in an attempt to discover various approaches to define and meet the wants and needs of the market are explored, is most applicable to which phase of the NPD process:

Select one:

a$.$ Product design

b$.$ Concept development

c$.$ Process design

d$.$ Pilot testing

e$.$ Pilot production