As regards walking to school, modern parents seem

单项选择题

Passage One Until last spring, Nia Parker and the other kids in her neighborhood commuted to school on Bus 59. But as fuel prices rose, the school district needed to find a way to cut its transportation costs. So the school’s busing company redrew its route map, eliminating Nia’s bus altogether. Now Nia and her neighbors travel the half mile to school via a "walking school bus" —a group of kids, supervised by an adult or two, who make the walk together. Like the rest of us, school districts are feeling pinched by rising fuel costs—and finding new way to adapt. The price of diesel fuel has gone up 34 percent in the past two years. For the typical American school district, bus bills total 5 percent of the budget. As administrators look to trim, busing is an inviting target, since it doesn’t affect classroom instruction (or test scores). More than one third of American school administrators have eliminated bus stops or routes in order to stay within budget. Many parents are delighted to see their kids walking to school, partly because many did so themselves: according to a 1969 survey, nearly half of school kids walked or biked to school, compared with only 16 percent in 2001. Modern parents have been unwilling to let kids walk to school for fear of traffic, crime or simple bullying, but with organized adult supervision, those concerns have diminished. Schools and busing companies are finding other ways to save. In rural areas where busing is a must, some schools have even chosen four-day school weeks. Busing companies instruct drivers to eliminate extra stops from routes and to turn off the engine while idling. They are also using computer software to determine the most fuel-efficient routes, which aren’t always the shortest ones. There could be downsides, however, to the busing cutbacks. If every formerly bused student begins walking to school, it’s an environmental win—but if too many of their parents decide to drive them instead, the overall carbon footprint can grow. Replacing buses with many more parent-driven cars can also increase safety risks. A 2002 report concluded students are 13 times safer on a school bus than in a passenger car, since buses have fewer accidents and withstand them better due to their size. And some students complain about the long morning hikes, particularly when the route contains a really big hill.

As regards walking to school, modern parents seem much concerned with the ______.

A．time spent on the way
B．changes in the route
C．kids’ physical strength
D．safety of their children