Numbers of suppliers in a purely competitive market dictate how easy it is to start a business or transform it in that sector.
Step-by-step explanation:
Entry an d Exit in a business sector means the ease of starting or transforming a business that is involved in a particular market sector.
In a purely competitive market the business is dictated by the market standards set by the completion of the various companies vying for a market share between each other.
The harder the competition at the top level, the harder it is for a new business to come up, similar is the case for when one or two companies dominate the hegemony in which case it is hard to grab a market share for the new entrant in the market.