Suppose that the price of a bottle of vitamins is $1.33 and that at that price the total quantity demanded by consumers is 75,000,000 bottles. how many firms will there be in this industry?

There is only one firm since it is a natural monopoly. This monopoly in a commerce in which high infrastructural prices and other blockades to pass qualified to the size of the market give the leading supplier in a commerce, frequently the first supplier in a market, a crushing advantage over possible competitors.