(b) pericycle

Explanation:

The lateral roots arise from the cell of pericycle and hence, the root branches are said to be endogenous in origin (arising from a layer inner to endodermis). The lateral roots help in absorption of water and mineral salts from the soil. The meristematic cells of the lateral root push through the endodermis and cortex and then pierce through the epidermis to come out to form the lateral root.