Final answer:
The most likely true local economic benefit to a city from hosting the NCAA Final Four is increased local spending and tourism, which can provide a temporary boost to the local economy.
Step-by-step explanation:
Among the options provided, increased local spending and tourism is most likely to be a true local economic benefit to a city from hosting the NCAA Final Four basketball tournament. Large-scale events like the NCAA tournament can draw visitors from outside the local area, leading to a temporary boost in spending on accommodations, dining, and other local attractions which can be beneficial for local businesses. This increased activity contributes to the local economic vitality, as opposed to long-term infrastructure improvements, which are not typical for such events. Additionally, such events are unlikely to cause a decrease in local tourism or result in no economic impact at all.