In substitution type of questions, some particular objects are assigned code names. Then a question is asked that is to be answered in the code language.

If water is called food, food is called tree, tree is called sky, sky is called wall, on which of the following grows a fruit ?

A. Water
B. Food
C. Sky
D. Tree
E. Wall
Answer: C . Sky


The fruits grow a 'tree' and 'tree' is called 'sky'.
So, the fruits grow on the 'sky'.