Heirloom Plants Are Treasured for Their Flavorful Produce and True-Breeding

Heirloom plants are treasured for their flavorful produce and true-breeding progeny that allow gardeners to avoid repeatedly purchasing seed from agribusiness conglomerates.What special effort is required to save seed from heirloom biennials such as carrots?

A) Since carrots produce large roots,they do not devote many resources to seed development.The roots must be trimmed before collecting seed.
B) Since carrots build up so much beta-carotene,they do not devote many resources to seed development.A yellow carrot variety will produce better seeds than a darker one.
C) Since carrots are related to wild weeds,they are often cross-pollinated.The green top must be bagged to ensure self-pollination.
D) Biennials do not produce seed until the second year of growth.Although carrot roots are normally harvested after one season,they must be allowed to grow another year for seed collection.