When a plant grows as mediated by growth hormones, which main plant organs are at work? a meristem and roots b stems and leaves c roots and stem d leaves and roots

Leaves and roots             

When a plant grows and is mediated by the plant’s growth hormones. Leaves and roots are usually the organs that are very busy in the process. Why? 

1. Leaves process photosynthesis, a process in the plants or autotrophs that enables them to create their own food with the use of sunlight (chlorophyll in leaves), carbon, water and nutrients. 
2. Roots expands and develop in structure. Since the plant is developing the roots of the plants need to collect more water and nutrients that allows and helps the leaves process photosynthesis. 

The answer is C roots and stem.

Plant hormones regulate plant growth, including stem and roots, as well as leaves formation. Plant organs are stem, roots, leaves. and reproductive structures. So, meristem from choice A cannot be the correct since it is a tissue. Among plant organs, plant hormones will have the bigger effect on roots and stem.