A、An hour before sunset. B、An hour after sunset. C、An hour before sunrise. D、An hour after sunrise. B新闻中提到航天飞机于下午8点39分，也就是日落一小时后

The space shuttle Endeavour and its crew of seven returned to Earth Wednesday, making a rare nighttime touchdown to wrap up "a two-week adventure" at the international space station. The shuttle landed in darkness Wednesday night after its scheduled landing was delayed by cloud cover. [9]The shuttle swooped through the darkness and landed on NASA’s illuminated runway at 8:39 p.m., an hour after sunset. The shuttle’s homecoming was a bit delayed. [10]Endeavour was supposed to land before sunset, but at virtually the last minute, clouds moved in. As the astronauts took an extra swing around the planet, the sky cleared enough to satisfy flight controllers and—after asking Gorie for his opinion—they gave him the green light to head home. It was only the 22nd space shuttle landing in darkness. Fewer than one-fifth of all missions have ended at nighttime; the last one was in 2006.