Final answer:
When the price of bus tickets increases, the opportunity cost of bus tickets also increases.
Step-by-step explanation:
The opportunity cost of bus tickets refers to the value of the next best alternative that is forgone when choosing to purchase the bus tickets. In this case, Alphonso's town raised the price of bus tickets from $0.50 to $1 per trip. As a result, Alphonso's new budget constraint will be steeper, and he will have to sacrifice more burgers to afford the same number of bus trips. This means that the opportunity cost of bus tickets has increased.