It is hard to find a safe environment for running.

　　题干大意：找一个适合跑步的安全环境很难。题目的关键词是"difficult to find"和"safe environment"，对应原文第二段第二句：All you need is a good pair of running shoes and a safe environment.原文是说你只需要一双好的跑鞋和一个安全的环境。题目所说的内容在文中并没有出现，故选C。