What type of weed completes its life cycle within one year?

Annual weeds are characterized by their ability to complete their entire life cycle, from germination to the production of seeds, within a single growing season, typically lasting less than a year. This quick life cycle allows them to rapidly proliferate in optimal conditions, making them particularly challenging to manage in agricultural settings. They emerge, grow, reproduce, and die off within a brief period, which is often around a few months depending on the environmental conditions.

In contrast, perennial weeds live for several years, returning year after year, while biennial weeds require two growing seasons to complete their life cycle. Invasive weeds, while they can include annual species, refer more broadly to non-native species that disrupt local ecosystems. Therefore, annual weeds are specifically defined by their one-year life cycle, making them the correct answer to this question.