When a flower has all the sets of whorls, it is described as a complete flower. Let's understand what this means and why the correct answer is option 'A'.

Explanation:
A flower is a reproductive structure found in flowering plants (angiosperms). It is made up of different parts, including sepals, petals, stamens, and pistils. These parts are arranged in whorls or circles around the center of the flower.

1. Whorls of a Flower:
- Sepals: The outermost whorl of a flower is known as the sepals. Sepals are usually green in color and are responsible for protecting the developing flower bud.
- Petals: The next whorl inside the sepals is called the petals. Petals are often brightly colored and play a role in attracting pollinators, such as insects or birds.
- Stamens: Inside the petals, we find the stamens. Stamens are the male reproductive organs of a flower and consist of two parts: the filament and the anther. The anther produces pollen, which contains the sperm cells.
- Pistils: The innermost whorl of a flower is made up of one or more pistils. Pistils are the female reproductive organs and consist of three parts: the stigma, style, and ovary. The stigma receives pollen, the style connects the stigma to the ovary, and the ovary contains the ovules, which develop into seeds after fertilization.

2. Complete Flower:
- A complete flower is one that possesses all four sets of whorls: sepals, petals, stamens, and pistils.
- In a complete flower, all the reproductive parts (stamens and pistils) are present, allowing for sexual reproduction to occur within the same flower.
- The presence of all whorls ensures that the flower is capable of fertilization and seed production.

Therefore, option 'A' (Complete) is the correct answer because it accurately describes a flower that possesses all the sets of whorls, including sepals, petals, stamens, and pistils.

Complete