选B。句意：“世界银行行长说，他热爱中国，这种热爱他记得早在童年时就开始了。”通过分析句子结构可知，The president of the World Bank says he has a passion for China 为主句，通过还原法可知定语从句是he remembers his passion for China starting as early as his childhood，从句中his passion starting 为动名词复合结构。his passion用which替代。when和where 虽然可以引导定语从句，但是它们在定语从句中是分别用来作时间状语和地点状语的，不能指代passion；what不能用来引导定语从句，故排除。