The word it” in paragraph 4 refers to .

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer
Ha Long Bay, located in Quang Ninh Province, Viet Nam, was recognized as a World Heritage Site by UNESCO in 1994. Over the years, Ha Long Bay has attracted numerous visitors who come to enjoy its breathtaking views and experience other activities.
Ha Long Bay is well-known for its beautiful scenery. With its thousands of rocks and caves emerging out of the water, Ha Long Bay has won international recognition. As visitors explore this magnificent place, there are always new surprises for them.
Cruise tours are very popular in Ha Long Bay. There are different cruise itineraries so tourists can visit many different caves, and experience the local culture and life on the water. Thus, a tour may last from several hours to a day, or even a night on board, which gives the visitors a truly superb experience.
Ha Long Bay cuisine presents another attraction for tourists. It is famous for its fresh seafood, such as crabs, prawns, and sea clams. A trip to Ha Long Bay is not complete without tasting the authentic local food served in many restaurants in the area.
Tourists can also do and see a lot in Ha Long Bay at a reasonable price. They can save money thanks to the availability of low-cost hotels and cruise tours. For those with more abundant travel budgets, there are also many options. They can enjoy the comfort and elegance of five-star hotels and luxury cruise ships.
The experiences of each visitor to Ha Long Bay vary. Some may remember waking up to a beautiful sunrise among the rocks, islets, and caves. Others may never forget their cave dinner or the breathtaking view from a mountain top overlooking the bay. However, they will all be left with the unforgettable memories of their Ha Long Bay tour.