1)Market power is: b. the firm's ability to influence the price of its product.

The sources of market power are whether your product is unique or differentiated from your competitors, and how many competitors you have.

Many competitors in the market with an identical product means you as the seller have no control - that's perfect competition.

You have some control if the product you sell is branded so that you can distinguish yourself from your competitors, even if there are lots of competitors - that's monopolistic competition.

Being the only seller gives you a great deal of control over your price or your level of output - that's monopoly power.

Being one of a few sellers gives you more control than if you haad more competition, but not as much control as a monopoly - that's an oligopoly.

2)The big difference between a pure or perfect competitor and a firm in monopolistic competition is in the type of products they sell.

A purely competitive firm sells a product that is identical to every other competitor. That type of firm has no power because a customer can't distinguish one product from another, and the consumer is only willing to pay the price that is set by the market.

In contrast, customers can distinguish among the products provided by monopolistic competitors, because they are branded products. Examples include peanut butter and other foods, toothpaste and other health products, and laundry and cleaning products. These competitors advertise the features of their products, and depend on brand-name recognition and advertising to increase their market share.