Answer is a)genus because lower the taxa ,more are the characteristics that the members within the taxon share.

The common characteristics between tomato and potato will be maximum at the level of their family (Option B).

Explanation:

- Taxonomy is the science of identifying, naming, and classifying organisms.
- Organisms are classified into different categories based on their characteristics. The categories are arranged in a hierarchical order.
- The hierarchy of categories from the broadest to the most specific is Kingdom, Phylum, Class, Order, Family, Genus, and Species.
- Tomato and potato belong to the Kingdom Plantae, which includes all plants.
- They also belong to the same Phylum, Anthophyta, which includes flowering plants.
- They belong to different Classes - tomato belongs to the Class Magnoliopsida, while potato belongs to the Class Liliopsida.
- They belong to the same Order, Solanales, which includes plants like tomato, potato, eggplant, and tobacco.
- They belong to the same Family, Solanaceae, which includes plants with similar characteristics such as having alternate leaves, solanine alkaloids, and flowers with 5 fused petals and 5 sepals.
- They belong to different Genera - tomato belongs to the Genus Solanum, while potato belongs to the Genus Solanum.
- They belong to different Species - tomato belongs to the Species lycopersicum, while potato belongs to the Species tuberosum.

Therefore, the common characteristics between tomato and potato will be maximum at the level of their Family (Solanaceae) because they have similar characteristics that are shared by other members of the same family.