参考答案

正确答案：C
解析：细节题。A选项和第一段中increasing numbers of people visit Antarctica every year矛盾；B选项和If you are on a small ship of up to 100 passengers, then you have the chance to go ashore every time矛盾；D选项和Rules made by the International Association of Antarctic Tour Operators(IAATO)cover such things as the size of the cruise ship allowed to enter Antarctic waters and also personal conduct at landing sites in Antarctica(国际南极旅游组织协会制定的规则涉及诸如什么规模的旅游船才允许进入南极水域, 个人在南极登陆点的行为规范等事项。)相矛盾, 游览船的大小是有限制的, 并非越大越好；而由刚才的这句话可以得知去南极的船必须要守规矩, 例如船的大小、在南极登陆后的个人行为方面都有相应的规定, 即C选项的内容。