Biennials get changed into annuals by

Step-by-step solution

Vernalization is a process in which the plants are exposed to certain periods of low temperature so that flowering can be induced in them. Biennials are plants that take two years to complete its life cycle. When these plants are subjected to artificial cold treatment and the correct temperature and photoperiods, they induce flowering in the first growing season itself, just like the annuals (biennials usually flower in the second year of their growing season).