Chargaff's rule are applicable to which of the following option ?

Single stranded DNA . Single stranded RNA . Both single stranded DNA and RNA . Double stranded DNA .

Double stranded DNA .

The double helix model for the structure of DNA involves base pairing between the two strands of polynucleotide chains. This proposition was also based on the observation of Erwin Chargaff that for a double stranded DNA, the ratios between Adenine and Thymine and Guanine and Cytosine are constant and equals one.