Assertion:  During differentiation, cells undergo few to major structural changes both in their cell walls and protoplasm.
Reason:  The living differentiated cells, that  have lost the capacity to divide can regain the capacity of division under certain conditions. This phenomenon is termed as redifferentiation.

Assertion (A) is true and Reason (R) is false.

The correct answer is Option (3)-Assertion (A) is true and Reason (R) is false.

The cells derived from root apical and shoot-apical meristems and cambium differentiate and mature to perform specific functions. This act leading to maturation is termed as differentiation. During differentiation, cells undergo few to major structural changes both in their cell walls and protoplasm. For example, to form a tracheary element, the cells would lose their protoplasm. They also develop a very strong, elastic, lignocellulosic secondary cell walls, to carry water to long distances even under extreme tension. 

Plants show another interesting phenomenon. The living differentiated cells, that by now have lost the capacity to divide can regain the capacity of division under certain conditions. This phenomenon is termed as dedifferentiation. For example, formation of meristems – interfascicular cambium and cork cambium from fully differentiated parenchyma cells. While doing so, such meristems/tissues are able to divide and produce cells that once again lose the capacity to divide but mature to perform specific functions, i.e., get redifferentiated. List some of the tissues in a woody dicotyledenous plant that are the products of redifferentiation.