P, Q, R and S are four major types of phytohormones. P is a phytohormone which functions mainly as a growth inhibitor. It promotes the wilting and falling of leaves. Q, R and S are phytohormones which all promote growth of plant in various ways like Q is responsible for the phototropism in plants while Ris involved mainly in shoot development. The phytohormone S helps in breaking the dormancy of seeds and buds. What is P, Q, R and S.

Explanation

P - Abscisic acid,
Q - auxin
R - Gibberellin
S - cytokinin