Vegetative propagation:
Vegetative propagation is the process by which plants reproduce asexually, without the production of seeds. It involves the growth and development of new plants from vegetative structures such as stems, roots, and leaves. This method of reproduction allows plants to produce genetically identical offspring, known as clones. Here are some key points explaining why vegetative propagation is the correct answer:

1. Asexual reproduction:
Vegetative propagation is a form of asexual reproduction, where new individuals are produced without the involvement of gametes or the fusion of genetic material. This is in contrast to sexual reproduction, which requires the production of seeds through the fusion of male and female gametes.

2. Vegetative structures:
Plants that have lost their capacity to produce seeds rely on vegetative structures to propagate. These structures can include stems, roots, leaves, buds, or specialized reproductive structures like bulbs, tubers, and runners.

3. Clonal offspring:
When a plant reproduces vegetatively, the resulting offspring are genetically identical to the parent plant. This is because they are derived from a single parent plant and do not undergo the genetic recombination that occurs during sexual reproduction. Clonal offspring ensure the preservation of desirable traits in horticultural crops and can be advantageous in terms of maintaining specific characteristics.

4. Methods of vegetative propagation:
There are various methods of vegetative propagation, including cutting, layering, grafting, and tissue culture. Cutting involves taking a portion of a stem or root and encouraging it to develop roots and grow into a new plant. Layering involves bending a low-growing stem to the ground and encouraging it to root before separating it from the parent plant. Grafting involves joining the stem of one plant (scion) to the rootstock of another plant, allowing them to fuse and grow together. Tissue culture is a laboratory-based method that involves growing plants from small pieces of plant tissue under controlled conditions.

5. Examples:
Some examples of plants that reproduce through vegetative propagation are potato, onion, garlic, strawberry, banana, bamboo, and many ornamental plants like roses and orchids. These plants have been selectively bred over generations, and their desirable traits are maintained through vegetative propagation.

In conclusion, plants that have lost their capacity to produce seeds reproduce through vegetative propagation. This method allows for asexual reproduction, the development of new plants from vegetative structures, the production of genetically identical offspring, and the preservation of desirable traits.