Final answer:
Total revenue is calculated by multiplying the price of the product by the quantity sold.
Step-by-step explanation:
Total revenue is calculated by multiplying the price of the product by the quantity sold. For example, if a store sells 100 cameras at a price of $200 each, the total revenue would be $20,000 (100 cameras x $200). Therefore, the correct option is a: Cameras sold and their price.