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：B。根据题干中的boost和ebikes sales in Europe可定位至第三段第二句，其中boost对应句中的spurring，ebikes sales in Europe对应句中的European sales。该句表示，2004年，电动自行车的电池价格下降，刺激了欧洲的销售。由此可知，是电动自行车电池价格的下降推动了本世纪初欧洲电动自行车销量的增长。B项符合题意，The falling prices of ebike batteries是对原文中the price of batteries used on ebikes fell的同义替换，故B项为正确答案。

错项排除：原文中提到，由于供应商多年来一直在为笔记本电脑、智能手机和电动汽车开发新技术，电动自行车行业正受益于电池的改良。由此可知，影响电动自行车的主要是电池的情况，而非自行车制造技术的优化，排除A项。原文中未提及短途旅行，也没有讨论制造电动汽车的成本对电动自行车销量的影响，故排除C和D两项。