单项选择题

PASSAGE ONE The other day my son asked me if he could ride up to his elementary school on his bike and meet his friend. He wanted the both of them to ride back to our house so they could play video games and jump on the trampoline. I have to admit, part of me wanted to say no. We can go pick him up or his parents can bring him over here, I thought. But my son is eleven years old now. And after all, I do let him ride his bike to school. But I also drive my daughter to school and I can see him on the way, making sure he is getting there safely. My husband thinks I am too overprotective. I don’t care to let my children walk anywhere without one of us going along. As you pull out of our neighborhood, there is a shopping center across the street.My son always asks if he can ride his bike or walk over to the drugstore by himself. But crossing that street is just too dangerous. The cars fly around the corner like they’re driving in a car race. What if he gets hit What is some teenage bullies are hanging out in the parking lot I want so much to give my children the freedom that I enjoyed having when I was growing up but I hesitate to do so because there are dangers around every corner. Too many kidnaps, too many sex offenders. I went online and discovered there are 41 sex offenders in my area alone. I honestly don’t think my mom worried about such things when her children were young. Growing up in the 1970s was indeed a different time. I never wore a helmet when I rode a bike.We were all over the neighborhood, on our bikes and on foot, coming home for dinner and then back out again until dark. We rode in the back of the truck, didn’t wear seatbelts. I walked to and from school every day… What is the author’s main purpose in writing this passage