Answer:
Option A
is a type of imperfectly competitive market
Step-by-step explanation:
An oligopoly is a market arrangement where a few number of producer/sellers dominate and control the market.
Usually, in this type of imperfect ,market, firms would always need to collude to increase their prices for their products which are relatively differentiated products
These firm together have a concentration ratio of more than 50% i.e they control more than 50% of the entire market share.
Answer
is a type of imperfectly competitive market