What are the three methods through which perennials can reproduce?

The correct answer highlights the three methods through which perennials can reproduce: seeds, rhizomes, and stolons.

Seeds allow perennials to reproduce sexually, leading to genetic variation in the offspring. This method involves the fertilization of ovules and produces a new plant that can grow independently under appropriate conditions.

Rhizomes are specialized underground stems that grow horizontally and can produce new shoots and roots at nodes. This method of asexual reproduction enables the plant to spread and occupy more space, as each new shoot can establish itself as a separate plant.

Stolons, also known as runners, are similar to rhizomes but grow above ground. They extend out from the main plant and can root at various points, giving rise to new plants. This method allows for quick colonization of an area and helps perennials to propagate efficiently.

The other options include methods that may apply to certain plant types or conditions, but they do not accurately represent the primary reproductive strategies for perennials. For instance, while grafting and layering are indeed propagation methods, they are not standard for most perennial plants, which typically rely on natural and more straightforward methods such as seeds, rhizomes, and stolons.