Clonal libraries used to determine the sequence of a microbial genome using the whole-genome shotgun approach are typically generated by

A)cloning small gene sized DNA fragments produced by breaking chromosomal DNA with ultrasonic waves.
B)cloning large DNA fragments produced by breaking chromosomal DNA with ultrasonic waves.
C)cloning random PCR fragments amplified from genomic DNA.
D)cloning large DNA fragments produced by restriction endonuclease cleavage.