The correct option is C It induces elongation of stem
Abscisic acid is a plant growth inhibitor. It induces dormancy in seeds to survive unfavourable conditions i.e., very high or very low temperature. It helps in the storage of seed for later use. It also helps in the closure of stomata and prevents water loss through it.
Auxins and gibberellins are plant growth promoters that help in the elongation of stem.