The correct option is B Flowering
Plants are controlled by the temperature and light falling on them for the process of flowering. It is termed as vernalization and photoperiodism respectively. Photoperiodism can be defined as the developmental responses of plants to the relative lengths of light and dark periods. Many flowering plants (angiosperms) use a photoreceptor protein, such as phytochrome or cryptochrome, to sense seasonal changes in night length, or photoperiod, which they take as signals to flower. Vernalization is the acquisition of a plant's ability to flower in the spring by exposure to the prolonged cold of winter, or by an artificial equivalent.