Given the question: Read the following article and select the best answer. Article: On Saturday nights, A.J.Coston doesn't get a lot of sleep. Usually three or four times a night, a loud bell rings, a red light flashes, and he has to jump out of his bed. That's because he's a weekend volunteer firefighter with Loudoun County Fire and Rescue Station 13 in Northern Virginia. During the week, he lives at home with his mom, dad and sister and does his main job which is going to high school. "I have always wanted to get into firefighting since I was a little kid watching fire trucks go by," he says. "One day on the Internet I noticed that Loudoun County offered a junior firefighter program." He was only 16, but he got it. Fighting fires is dangerous work. Firefighters never stop practicing the skills they need to stay safe. Once Coston learned those skills, he was allowed to work inside burning buildings. "Teamwork is most important," he says. "It's the whole team that puts the fire out." Firefighters feel great about helping people. "My most unbelievable call was probably the time four kids were struck by lightning," says Coston. He will be off to college next fall, building on his dream job. "I'll get my degree in emergency medical care. and then work in a fire and rescue company for a while. I want to be a flight doctor on a helicopter in the end, but I will never forget the days as a firefighter. These are my unforgettable experiences," he says. Question: Coston can't sleep well on Saturday nights because _ . - he has to work part-time at weekends - he has some sleeping problems - he has to do his job as a volunteer firefighter - he alway
The answer is:
he has to do his job as a volunteer firefighter