Which two of the following models will not be able to give the desired outcome if user’s participation is not involved?

A. Waterfall & Spiral
B. RAD & Spiral
C. RAD & Waterfall
D. RAD & Prototyg

Explanation: Active Participation of user is involved in all the four phases of RAD model and in case of the Prototyg model we need user’s presence/involvement every time a new prototype is build or designed.