Answer:
Running into an old friend who is in town for one day.
Explanation:
The term "fortuitous" refers to a chance occurrence, a surprising and unexpected event that happened, a fortunate event. This word is used to talk about things that happened unplanned and completely unexpected.
A fortuitous event means an event that happened so suddenly and unexpectedly that it leaves you shocked and completely unforeseen. Such an event is wholly unexpected and surprising. So, running into an old friend who's in town for a single day is a fortuitous event, for it is a chance encounter and not something that happens often or even planned.
Thus, the correct answer is the last/ fourth option.
