根据短文内容，在 A、B、C、D四个选项中选择一个正确的答案。
What does Beijing's Palace Museum look like at night? Many people don't know the answer to this question, as it closes at around 4:30 p.m. in winter and 5:00 p.m. in summer. However, to celebrate the Lantern Festival, Beijing's Palace Museum opened its door to the public after dark——for two nights only. That's a first in 94 years!
Although people could get free tickets on the museum's website, it was difficult to get a ticket. The website even stopped working for a while because too many people visited it at the same time. Zhang Zhifu, a 77-year-old woman, received a ticket from the museum as a gift. "I grew up in Beijing and I visited the Palace Museum every year, but I never got to see it at night. It is truly an honor." She said.
In the past celebrating the Lantern Festival was a tradition for the imperial(皇帝的)family. "We want to pass the tradition on and give people more festival experience." Said Shan Jixiong, the head of the Palace Museum. On the night of February 19th, 2019, about 3,000 visitors spent the Lantern Festival in the Palace Museum.
Beijing's Palace Museum closes at around 4:30 p.m. in _________.
A.spring
B.summer
C.autumn
D.winter