In a major metropolitan area, one chain of coffee shops has gained a large market share because customers feel its coffee tastes better than that of its competitors. two taxi companies serve most of the market in a big city. consumers don't care which taxi company they takeâif they decide it's worth taking a taxi, they flag down the nearest one. the government has granted the u. s. postal service the exclusive right to deliver mail. there are hundreds of high school students in need of algebra tutoring services in philadelphia. dozens of companies offer tutoring services, and the parents who seek out tutors view the quality of the tutoring at the different companies to be largely the same.

The correct options are as follows:
1. In a major metropolitan area, one chain of coffee shops has gained a large market share because customers feel its coffee tastes better than that of its competitors.
The scenario given above does not describe a competitive market. This is because, the product that is concerned is not a standardized product. For a market to be competitive, the product been sold must be identical and homogeneous.

2. Two taxi companies serve most of the market in a big city. consumers don't care which taxi company they take, if they decide it's worth taking a taxi, they flag down the nearest one.
The scenario above does not describe a competitive market. This is because, the market is not made up of many sellers. For a market to be competitive, there must be many sellers.

3. The government has granted the U.S. postal service the exclusive right to deliver mail.  
The scenario above does not describe a competitive market. This is because, the entry to the market had been restricted by the US government. For a market to be considered competitive, there must be free entry into the market, no barrier must be in place to prevent those who want to enter the market.

4. There are hundreds of high school students in need of algebra tutoring services in Philadelphia. dozens of companies offer tutoring services, and the parents who seek out tutors view the quality of the tutoring at the different companies to be largely the same.
The scenario above describe a competitive market. This is because, it meets all the criteria for a competitive market. There are many producers, many consumers and a homogeneous product.