If T.S. of young dicot stem is stained with Iodine solution, which of the following region will be stained dark blue?

Step-by-step solution

Iodine solution is used to stain starch. In dicot stem, the innermost layer of the cortex is called the endodermis. The cells of the endodermis are rich in starch grains and the layer is also referred to as the starch sheath. Thus staining gives blue black colour due to starch.