ABA (Abscisic Acid) is called a stress hormone.
A. How this hormone overcome stress conditions ?
B. From where where does this hormone get released in leaves ?

Explanation

Stress hormone ABA (Abscisic Acid) gives signals to stomata to get closed, whereever there is scarcity of availability of water to the plant. This precents the loss of water through transpiration by leaves. It also increases the tolerance of plants to various kinds of stresses.
B. It (ABA) is realeased or teansported from stem apices to leaves.