Which enzyme is synthesized by gibberellins to break seed dormancy in wheat and barley?

The rosette habit of cabbage can be changed by the application of

Which gibberellin was discovered first?

Dormancy of seed is broken by

$A$ : Seeds do not sprout when $ABA$ is overcome by Gibberellins. $R$ : $GA$ inhibits protein and $RNA$ synthesis.

Name the plant growth regulator which,upon spraying on sugarcane crop,increases the length of stem,thus increasing the yield of sugarcane crop.