When electronic markets permit prices to change faster even daily as a function of demand and supply then this practice is called:

competitive pricing
e-marketing pricing
yield management pricing
none of the above

The correct answer is: C. yield management pricing.

Yield management pricing is a pricing strategy used by airlines, hotels, and other service providers to maximize revenue by adjusting prices according to demand. This strategy is often used in conjunction with electronic markets, which allow prices to be changed quickly and easily.

Competitive pricing is a pricing strategy in which businesses set prices based on the prices of their competitors. This strategy is often used in markets with a large number of competitors.

E-marketing pricing is a pricing strategy that takes into account the unique characteristics of the online environment. This strategy often involves using dynamic pricing, which allows prices to be changed based on factors such as demand, time of day, and customer behavior.

None of the above is not the correct answer because it does not describe the pricing strategy in question.