Questions 168~171 refer to the following brochure.
Welcome to Denver, Colorado's bustling metropolis! Getting around the city has never been easier with our efficient subway system. Our network currently consists of three major lines that run throughout the city, each with its unique purpose. 
The first line, called the Silver Line, connects all major government institutions, the train station, and the airport. The Silver Line starts at Union Station in downtown Denver and runs eastwards towards the airport, stopping at several important government buildings along the way. The journey from Union Station to the airport takes approximately 40 minutes. 
The second line, the Gold Line, is perfect for tourists and visitors. The Gold Line starts at the iconic Civic Center Park and passes through several popular tourist destinations, such as the Denver Art Museum, the Denver Zoo, and the Red Rocks Amphitheatre. The entire journey from Civic Center Park to Red Rocks takes around 50 minutes.
The third line is the Circle Line. This circular route is ideal for commuters and residents alike, connecting neighborhoods and suburbs on the outskirts of the city. The Circle Line takes approximately 60 minutes to complete a full loop and runs every 10-15 minutes throughout the day. 
Our subway system makes traveling around Denver a breeze, with each line serving a unique purpose. Whether you're heading to the airport on the Silver Line or taking the Circle Line to explore the city's vibrant neighborhoods, our color-coded system makes it easy to get around.
【題組】168.According to the brochure, what is the Circle Line's route like?
(A)It runs eastwards towards the airport.
(B)It connects neighborhoods and suburbs on the outskirts of the city.
(C)It passes through several important government buildings.
(D)It completes a full loop.