I was most favorably struck by the assurance with which the boy answered all my questions.

A．that geniuses are fond of playing games, too
B．that geniuses are as creative as most children with a set of interesting toys
C．how geniuses turn ideas into reality in different ways
D．why making different combinations can work wonders

A．referred to numerous books
B．made use of drawings and graphs
C．compared it with many other problems
D．approached it from different angles