b$.$ The branch manager wants to improve the service and suggests dispatching buses every $0\mathrm{.}5$ minutes. The manager argues that this will reduce the average traveling time from the airport to Avis offices to $2\mathrm{.}5$ minutes. Is the manager correct?

Yes, the manager is correct.

No$,$ the manager is not correct.

It depends on the time of day.

There is insufficient information to answer this question.