What Is the Reason for Partial Digestion of Genomic DNA

What is the reason for partial digestion of genomic DNA with restriction enzymes?

A) generating blunt ends,when only enzymes that leave sticky ends are available
B) generating sticky ends,when only enzymes that leave blunt ends are available
C) cutting only one strand of a restriction site,leaving a nick instead of a break
D) producing fragments that are slightly shorter than a complete digest would produce
E) producing fragments that are slightly longer than a complete digest would produce