After a metagenomics researcher collects a mixed sample of DNA,what next step allows this DNA to be studied?

A) The DNA fragments are each ligated into a cloning vector to create a DNA library.
B) The pieces of DNA are ligated together into one complete "genome" so they can be sequenced.
C) The species responsible for each DNA are identified and individually cultured.
D) DNA is reconstructed into chromosomes by using the human genome as a scaffold.