Commercial banks make most of their income from interest _______

Commercial banks make most of their income from interest _________ on loans and investments in stocks and bonds
A、earn
B、earned
C、to earn
D、was earned
【正确答案】：B
【题目解析】：earn interest 表示“赚取利息”,这里interest应该是被赚,用过去分词earned表示被动,同时修饰前面的名词interest.