These flowers show radial symmetry

The correct option is Brassica.

To understand why this is the correct answer, let us break down the concepts of floral symmetry in plants:

1. Radial Symmetry (Actinomorphic):
A flower exhibits radial symmetry (or is actinomorphic) when it can be divided into two equal radial halves along any radial plane passing through the center. Examples of plants with radial symmetry include Brassica (mustard), Datura, and Chilli.

2. Bilateral Symmetry (Zygomorphic):
A flower exhibits bilateral symmetry (or is zygomorphic) when it can be divided into two similar halves only in one particular vertical plane. Examples include plants belonging to the family Fabaceae, such as Pisum (pea), Cassia, and Trifolium (clover).

Conclusion:
Among the given options, Cassia, Pisum, and Trifolium have zygomorphic (bilateral) flowers. Only Brassica has actinomorphic flowers that show radial symmetry.