单选题 Many countries are famous for unique and delicious foods. China, Italy, France, India, and Japan are just some of the countries with famous national cuisines. In the past, people had to travel great distances in order to sample foods from other countries. Today, it has never been easier to try food from a different country every day. One of the most popular foods around the world is pizza. Though pizza has historical and cultural ties to Italy, many different types of pizza have developed outside of Italy and several have been adopted as signature dishes of the respective region. Pizza first appeared in Italy as a type of flat bread that was inexpensive and easy to make. By the 18th century, residents around Naples in southern Italy were famous for their baked flat breads covered in tomato sauce. To this day, people still travel to Naples to sample pizza in its birthplace and Neapolitans (residents of Naples) are proud of this heritage. Indeed, the city continues to be famous for its delicious pizza. One of the first (and still most popular) varieties of pizza is called the Margherita, named after Queen Margherita of Savoy. This variety was her favourite because the colours of the ingredients matched the Italian flag — red (tomatoes), white (mozzarella cheese), and green (basil leaves). With increased trade, travel, and immigration throughout the 18th and 19th centuries, cultural traditions and cuisines spread around the world. Today, pizza is very popular in many countries, including the United States. New York City and Chicago are particularly famous for their unique styles of pizza. Pizzas today are also available with nearly every topping imaginable: mushrooms, peppers, sausage, pineapple, and anchovies, to name only a few. If you can think of it, chances are that someone's already tried putting it on a pizza!1)Which of the following best describes "signature dishes" (Para. 2, Line 2)