Schumpeterian Models of Technological Progress Incorporate the Following Principle(s)

Schumpeterian models of technological progress incorporate the following principle(s) :

A) innovations are the result of intentional application of costly resources to R&D activities to create new products, ideas, processes, techniques, etc.
B) competition among firms becomes a process of creative destruction.
C) eventually monopoly producers dominate the economy and technological progress stops.
D) a and c only.
E) a and b only.