Smaller plant virus is

✅Explanation:
Satellite viruses are the smallest known plant viruses. They are unique in that they depend on helper viruses for their replication and encapsidation. They possess very small genomes, typically encoding only a few proteins.

📌Other Options Explanations:
-Option A: SBYV (Soybean Yellow Bud Mosaic Virus): SBYV is a single-stranded RNA virus that belongs to the Luteoviridae family. While relatively small, it is larger than satellite viruses.
-Option B: TMV (Tobacco Mosaic Virus): TMV is a single-stranded RNA virus that was the first virus ever to be discovered. It has a rod-shaped structure and is larger than satellite viruses.
-Option D: PVX (Potato Virus X): PVX is a flexuous, rod-shaped virus belonging to the Alphaflexiviridae family.