With diffusion of innovation:
A.
once a product enters the market, very similar products will enter within a very short period of time.
B.
one new product will produce ancillary product invention (e.g., video cassettes created a market for cassette holders).
C.
not all consumers accept a new product at the same time because adoption of a product spreads slowly throughout the population.
D.
product changes by one competitor lead to similar product changes by another competitor.
Answer: C