( A ) the proportion of adenine in relation to thymine varies with the organism
( B ) there are two strands which run parallel in the 5′→3′ direction
( C ) there are two strands which run antiparallel one in 5′→3′ direction and other in 3′→5′
( D ) the total amount of purine nucleotides and pyrimidine nucleotides is not always equal
