Which of the following descriptions is NOT true of heterochromatin?

A) It remains in a highly condensed state throughout the cell cycle.
B) It makes up most chromosomal material and is where most transcription occurs.
C) It exists at the centromeres and telomeres.
D) It occurs along one entire X chromosome in female mammals when this X becomes inactivated.
E) It is characterized by the absence of crossing over and replication late in the S phase.