Practice question

Degrading ARR-B (B) is correct here. This is core Cytokinin: once you know the definition or pathway step, Degrading ARR-B is the clear fit. The wrong ones are A) Activating ARR-B; C) Degrading ARR-A; D) Activating IPT. If the topic is about gradients or potentials, water/solutes move from higher to lower of the relevant quantity.