i think ___right to tell him the truth

题目

i think ___right to tell him the truth
A.that
B.this
C.these
D.it
please tell me why

答案

答案 D
解析 这里 it作形式宾语 真正的宾语是后面的 to tell him the truth
又如 I find it difficult to work late.
语法上规定只有it可作形式宾语