【正确答案】 C

【答案解析】从句的正常语序应为obtaining fresh water is not the least of which。例如：A genius is a man who does unique things of which nobody would expect him to be capable．天才就是指能够完成别人认为无法完成的事情的人。Life is a flower of which love is the honey．人生是花朵，爱情是花蜜。