Idioms and Phrases - Verbal and Reasoning

In the following questions four alternatives are given for the idiom/phraseitalicised and underlinedin the sentence. Choose the alternative which best expresses the meaning of idiom/phrase.
Q1:

Though he has lot of money, yet all his plans are built upon sand.

A established on insecure foundations

B based on inexperience

C resting on cheap material

D resting on immature ideas

ANS:D - resting on immature ideas

No answer description is available.