Which of the given plant hormone is known as stress hormone?

Solution:

Abscisic acid (ABA) is commonly known as the stress hormone in plants. It plays a crucial role in mediating plant responses to various environmental stresses such as drought, salinity, and cold. ABA promotes stomatal closure to reduce water loss during drought, induces dormancy in seeds and buds, and helps plants adapt to adverse conditions. Auxins, cytokinins, and ethylene are other plant hormones with different primary functions related to growth, cell division, and fruit ripening, respectively.