Final answer:
The best meaning for 'capsule' in the provided sentence is 'A. a dry fruit or pod which is made up of several parts or carpels, and opens to discharge the seeds.' This term is tied to the dispersal of seeds from the plant's fruit.
Step-by-step explanation:
The best meaning for 'capsule' as it is used in the sentence provided would be 'A. a dry fruit or pod which is made up of several parts or carpels, and opens to discharge the seeds, as, the capsule of the poppy, the flax, the lily, etc.' This definition aligns with the biological context of how the term is typically used in relation to plants and their reproductive structures. A capsule is part of the fruit, which develops from the ovary after fertilization and is meant to protect and aid in the dispersal of the seeds.
In botany, fruits are classified as simple, aggregate, multiple, or accessory. The structure known as the pericarp is a collective term for the fruit's protective layers - the exocarp, mesocarp, and endocarp. When a plant's fruit is a dry type, the capsule is known for opening to release the seeds once the fruit has matured; this type of fruit is classified as 'dehiscent'.