When a plant grows as mediated by growth hormones, which main plant organs are at work?

Stems and leaves

The shoot system of plant consist of two vegetative parts called as stems and leaves. The shoot system grows above the ground and absorbs the light energy from sun to conduct photosynthesis necessary for plant growth and nourishment. The stem region exhibit active meristems which are the cells which undergoes quick and rapid differentiation due to the action of hormone like auxin and giberellins which causes cell differentiation, specialization to different functions, cell elongation to facilitate plant growth.  

b. read the phase at the intersection of any given temperature and pressure.

correct answer is a. and d.