A growing number of U.S. bike riders are attracted to electric bikes for convenience, health benefits and their fun factor. Although ebikes first appeared in the 90s, cheaper options and longer-lasting batteries are breathing new life into the concept.

        Established bike companies and startups are embracing ebikes to meet demand. About 34 million ebikes were sold worldwide last year, according to data from eCycleElectric Consultants. Most were sold in Europe and China, where the bikes already have exploded in popularity. Recently, the U.S. market has grown to 263,000 bikes, a 25% gain from the prior year.

        The industry is benefiting from improved batteries as suppliers over the years developed technology for laptops, smartphones and electric cars. In 2004, the price of batteries used on ebikes fell, spurring European sales.

        But lower cost options are emerging, too. This month, three U.S. bikeshare companies, Motivate, LimeBike and Spin, announced electric bicycles will be added to their fleets. New York-based Jump Bikes is already operating an electric bikeshare in Washington, D.C., and is launching in San Francisco Thursday. Rides cost $2 for 30 minutes.

        The system works like existing dockless bikeshare systems, where riders unlock bikes through a smartphone app. “This is the beginning of a long-term shift away from regular pedal (踏板) to electric bikes,” said Jump Bikes CEO Ryan Rzepecki. “When people first jump on an ebike, their face lights up. It’s exciting and joyful in a way that you don’t get from a regular bike.”

        Two years ago, CEO Chris Cocalis of Pivot Cycles, which sells high-end mountain bikes, found that U.S. bike shops weren’t interested in stocking ebikes. Some retailers warned Cocalis that they’d drop the brand if it came out with an electric bike.

        Now that sales are taking off, the vast majority of bike dealers are asking Cocalis when he’ll make an ebike available. “There’s tremendous opportunity to get a generation of people for whom suffering isn’t their thing,” Cocalis said. “Ebike riders get the enjoyable part of cycling without the massive suffering of climbing huge hills.”

解析：C。文章开头就提到了电动自行车，根据ebikes和题文同序原则定位至第一段第二句。该句表示，虽然电动自行车最早出现在上世纪90年代，但低廉的价格和更耐用的电池为这一概念注入了新的活力。由此可知，电池的改良使得电动车流行起来，同时第三段首句也提到电动自行车行业受益于电池的改良。C项符合题意，其中become popular对应首段第二句中的breathing new life into the concept，the emergence of improved batteries指的就是该句中的longer-lasting batteries，故C项为正确答案。

错项排除：文章开头说到，越来越多的美国自行车骑手被电动自行车的便利、健康和有趣所吸引，但并没有说它们的健康效益和趣味性高于成本，A项属于过度推断，故排除。原文第一段表示，20世纪90年代是电动自行车首次出现的时间，并非引起人们注意的时间，B项混淆概念，故排除。原文第一段说到，但更低廉的价格和更耐用的电池为这一概念注入了新的活力，因此价格和电池是电动自行车流行的原因，并非源于人们的环境意识，D项错误。