Viruses that infect plants usually have

1. dsRNA
2. dsDNA
3. ssRNA
4. ssDNA

The correct option is C ssRNA
Body of a virus is composed chiefly of a protein coat and a core that contains the genetic material. Viruses contain either RNA or DNA as the genetic material and never both. In general, viruses that infect plants have single stranded RNA (ssRNA) while those that infect animals may have either single or double stranded RNA (ssRNA or dsRNA) or double stranded DNA (dsDNA).

Approximately around 70% of viruses infecting plant are ssRNA, 20% are ssDNA and rest are either dsRNA or dsDNA.

ssDNA is advantageous due to it's ability to infect and duplicate it's genome faster.