Regarding DNA libraries, which of the following statements is true?

Regarding DNA libraries, which of the following statements is true?

A) 

DNA libraries are made by cutting the DNA of the organism

B) 

Each cell contains only one fragment of the genome

C) 

The entire genome is represented in the population as a whole

D) 

Colony blots can be used to determine which cells contain the gene of interest

E) 

All of these are true