• Genome Architecture of Hepadnaviruses (e.g., Hepatitis B Virus):
• Mature extracellular virions (Dane particles) contain a unique circular, partially double-stranded DNA genome ($pprox 3.2\text{ kb}$):
• Minus ($-$) strand: Complete, full-length, covalently linked at its $5'$ end to the viral reverse transcriptase/polymerase protein.
• Plus ($+$) strand: Incomplete and variable in length ($50 - 80\%$ of the circle), creating a single-stranded gap region.
• Upon infecting a host hepatocyte, the viral polymerase completes the positive strand, converting it into covalently closed circular DNA (cccDNA).
• nalysis:
• (Partially double-stranded DNA): Correct.

Correct option: (3) Partially double-stranded DNA