Answer:
e) It is the ratio of a firm's sales revenues or unit sales to those of the industry.
Step-by-step explanation:
Market share is the term used to describe the share in total sales of the market for the particular product produced by the organization in concern.
Individual firm's market share =

This, clearly relates to statement (e) in the option as that statement includes the ratio of firm's sales to the sales in the market.
Therefore, correct option is
Statement e)