LO $1-2$

$3.$ The efficient frontier is gifyen by the cheapest company in the industry. True or false?

$4.$ There can be no more than two firms on the efficient frontier. True or false?

$5.$ Two retailers compete on costs and the ambience of their retail stores. They are identical in all other dimensions of customer utility. Retailer A is cheaper than retailer B$.$ Retailer A also has the better ambience. Does this mean that retailer A is on the efficient frontier? Yes or no$?$