What is a nucleosome?

A.
a part of a chromosome in which the DNA molecule is wound around a ball of histone protein molecules

B.
one of the chromosomes in the nucleus of a eukaryotic cell with all of its associated protein

C.
an area in the nucleus of a eukaryotic cell where ribosomes are made from RNA and protein

D.
a small nucleus containing all the genetic material in a eukaryotic cell