Final answer:
An increase in the quantity of tickets available would most likely increase the consumer surplus received by Reds fans.
Step-by-step explanation:
The event that would most likely increase the consumer surplus received by Reds fans is d) An increase in the quantity of tickets available.
Consumer surplus is the difference between the price a consumer is willing to pay for a good or service and the actual price they pay. When the quantity of tickets available increases, it leads to a larger supply of tickets in the market. This increase in supply can result in lower prices, allowing Reds fans to obtain more tickets at a lower cost, thereby increasing their consumer surplus.