Inefficiency exists in a market when a good is

a. not produced because buyers do not value it very highly.

b. not distributed fairly among buyers.

c. not being produced by the lowest-cost producers.

d. being consumed by buyers who value it most highly."

d. being consumed by buyers who value it most highly."

Explanation:

Since the efficiency arises when optimal amount of each good and service is being produced and consumed in the economy.

Hence it can be said that inefficiency exists in the economy when a good not being consumed by the consumer who value it highly.