【正确答案】 C

【答案解析】[试题分析] 细节推断题。
[详细解答] 第三段第一句Mountaineering is a sport and not a game．There are no man-made rules，as there are for such games as golf and football告诉我们登山与其它运动的区别正是rules，所以，答案为C。