Explain why they are considered a oligopoly How has the costly requirements of research and development along with patent protection affected the market structure of the pharmaceutical industry before covid-19?

Basically You need to select 1 pharmaceutical company that produces a product that is with patent protection and are a monopoly.

Explain why they are considered a oligopoly How has the costly requirements of research and development along with patent protection affected the market structure of the pharmaceutical industry before covid-19?