Which type of dermal tissue is commonly known as bark?
epidermis
periderm
cuticle

The correct answer is Periderm.

In plants which undergo  secondary growth, the periderm, replaces the epidermis and becomes bark.

The periderm is a multilayered tissue that is different from the  epidermis which is single layered. It is made of cork cells (phellem) , phelloderm and phellogen (or cork cambium).

Cork cells are nonliving cells found covering the outside  of roots and stems to provide  protection and  insulation to the plant.

 The periderm serves to protect the plant from injury, pathogens, excessive water loss and provides insulation for the plant.