Answer the following question: Read the article and select the best answer. Article: Welcome to Windsor Castle, the oldest and largest occupied castle in the world. Windsor is one of the official residences of the Queen, who sometimes stays here. Audio tours Free audio tours are available on leaving the Admission Centre at the start of your visit. There is a descriptive audio tour for blind and poor sighted visitors. Guided tours Visitors can explore the history of the Castle through a tour of the Precincts with an expert guide. Tours depart at regular intervals throughout the day from the Courtyard and finish at the entrance to the State Apartments. Visitors with children For those visiting with children, a special family tour and various activities are offered during school holidays and at weekends. Please note that, for safety reasons, pushchairs are not permitted in the State Apartments. However, baby carriers are available to borrow. St George's Chapel Visitors arriving at the Castle after 15:00 from March to October are advised to visit St George's Chapel first before it closes. Shopping Shops offer a wide range of souvenirs designed for the Royal Collection, including books, postcards, china, jewellery, and children's toys. Please ask at the Middle Ward shop about our home delivery service. Refreshments Bottled water can be purchased from the Courtyard and Middle Ward shops. From April to September ice cream is also available. Visitors wishing to leave the Castle for refreshments in the town may obtain reentry permits from the castle shops. Eating and drinking are not permitted in the State Apartments of St George's Chapel. Photography and mobile phones Non-commercial photography and filming are welcomed in the Castle. Photography, video recording and filming are not permitted inside the State Apartments of St George's Chapel. Mobile phones must be switched off inside the State Apartments and St George's Chapel in consideration of other visitors. Security As Windsor Castle is a _ , visitors and their belongings should get through airport-style security checks. For safety and security... Question: In the last part, a "working royal palace" refers to one _ . Options: A: still being constructed B: still used by the royal family C: where the Queen usually works D: where works of art are on show
Answer:
B