The correct option is B Genus
Genus is the category below family and forms the first word of a scientific name. A group of closely related species forms a genus.
Family is a category that has a group of related genera.
A group of closely related families forms an order.
A group of closely related orders forms a class.
A division is a category below Kingdom, where classification is based on common features. Organisms in a division share the same set of characteristics that distinguishes them from another division. The same category is called phylum in the Kingdom Animalia.
Potato (Solanum tuberosum) and tomato (Solanum lycopersicum) belong to the same genus Solanum. Hence, they have a maximum level of similar characteristics at the genus level.