Which type of annual weed starts growth in the fall?

The correct choice is winter annuals because these types of weeds germinate and begin their growth in the fall. Winter annuals typically thrive during the cooler months and complete their life cycle by flowering and producing seeds in the spring or early summer. This life cycle allows them to take advantage of the seasonal changes and the environmental conditions favorable to their growth during the colder months.

In contrast, summer annuals germinate in the spring or early summer, which is not conducive to their growth during the fall and winter months. Biennial weeds have a two-year life cycle that begins with growth in the first year, followed by flowering and seeding in the second year, while perennial weeds live for multiple years and can grow during various seasons but do not specifically start their life cycle in the fall.