Which of the following statements about nuclear genome organization is CORRECT?

A、NucleolarorganizerregionsareportionsofchromosomeswhereribosomalRNAgenesareclusteredandtranscribed.;
B、Centromeresaresequenceslocatedattheendsofeachchromosome.;
C、Telomeresarewheresisterchromatidsadheretoeachotherandwherespindlefibersattachduringcelldivision.;
D、Chromosomeorganizationisrandomintheinterphasenucleus.