If the price elasticity of X is .67, a "sale" on X will

a. increase total revenue

b. decrease total revenue

c. will neither increase nor decrease total revenue

d. none of the above

Option (d) is the correct answer to this question

The price elasticity of demand is 0.67, which means that a 1 percent fall in price causes a 0.67 percent increase in demand for product X. However, the sale of product X is affected by many factors such as the price of the product, income of the consumer, price of the related product, and so on.

It cannot be determined whether the total revenue will increase, decrease or remain constant because it is not mentioned that the sale on X is due to the price change. As a result, options a, b, and c are incorrect.