Hormone which helps the plants to cope with stress is:

Correct option is A

Abscisic acid (ABA) is a stress hormone in plants. It helps plants survive drought, salinity, and cold stress by:
Closing stomata to reduce water loss.
Inducing seed dormancy under unfavorable conditions.
Regulating stress-related genes to protect plant cells.
Thus, the correct answer is (a) ABA.