Answer:
Option D, Sample 3 is the sample extracted from a virus
Explanation:
Uracil is less expensive as compared to thymine and hence it is found in RNA. Also, RNA virus has RNA or single stranded DNA. The RNA of virus has Uracil instead of thymine in its genetic material
Hence, option D is the correct answer.
Option A is incorrect because sample 2 has two strands while virus has only 1 strand
Option B is incorrect because sample 1 has a circular DNA while virus as linear genetic material
Option C is incorrect because sample 4 has 2 stands while virus has only 1 strand and it also has thymine instead of uracil