Final answer:
Option e, P/Q ratings and advertising, is not a factor in determining a company's unit sales and market share of cameras.
Step-by-step explanation:
The correct option that is not a factor in determining a company's unit sales and market share of entry-level or multi-featured cameras in a particular geographic region is option e, P/Q ratings and advertising. P/Q ratings and advertising may influence consumer perception and purchasing decisions, but they do not directly contribute to the factors mentioned in the other options, such as the number of camera models, warranty period, tech support budget, credit rating, special utility features, promotional discounts, wholesale selling prices, and retailer stocking.