Leaves of Grass was just the expression of Walt Whitman’s own se

Leaves of Grass was just the expression of Walt Whitman’s own set of （ ） principles.
A、​philosophic
B、psychological
C、moral
D、aesthetic
【正确答案】：D
【题目解析】：Leaves of Grass只是沃尔特·惠特曼自己的一套美学原则的表现。philosophic——哲学；psychological——心理的；moral——道德的；aesthetic——美学的。故选D。