Final answer:
The correct option for searching for Nightly Extra Vacations in DBL is (C) Last Call Vacations. This option is associated with last-minute deals on short-term stays.
Step-by-step explanation:
The tower option in DBL that allows you to search for Nightly Extra Vacations is (C) Last Call Vacations. Exchange Trading is typically related to the trading of ownership such as timeshare weeks, Nightly Rental refers to regular nightly bookings, and Hotel Stays are simply stays at hotels. Last Call Vacations often include deals on short-term nightly stays, possibly with extra bonuses or discounted prices for last-minute bookings.