Sequencing a Genome Requires Breaking It Up into Small Overlapping

Sequencing a genome requires breaking it up into small overlapping fragments of which the DNA sequences can be determined in a sequencing reaction. In map-based sequencing, sequenced fragments are ordered into the final genome sequence with the use of genetic and physical maps. In whole-genome shotgun sequencing, the genome is assembled by comparing overlap in the sequences of small fragments.
-A contig is

A) a set of molecular markers used in genetic mapping.
B) a set of overlapping fragments that form a continuous stretch of DNA.
C) a set of fragments generated by a restriction enzyme.
D) a small DNA fragment used in sequencing.