Answer:
Step-by-step explanation:
First scenario: The answer is No, not many sellers. The drug of the pharmaceutical company has patent right and it is the only firm selling this product. This makes the company a monopolist (single seller)
Second scenario: No, not an identical product. Cable company and phone company produce different products. Cable companies majorly deal with television access.
Third Scenario: no, not many sellers. One firm is dominating the market and customers prefers this. Its product has been differentiated and it can charge its own price.
Fourth scenario: yes,meets all assumptions. The socks are identical and consumers do not care about the seller because the same utility will be derived from the socks.