The correct option is B Guanine rich repeats
Telomeres are the structures present at the ends of linear eukaryotic chromosomes and have many tandem copies of a short oligonucleotide sequence. This sequence has mostly guanine residues in one strand and cytosine in the complementary strand. The G rich strand is longer leaving a region of single-stranded DNA of up to a few hundred nucleotides at the 3’ end which serves as primer for its elongation by telomerase enzyme. Thus, telomeres are rich in guanine residues. Correct answer is A.