Correct Answer - C
The phellem or cork cells are dead these are impervious tow water due to suberin deposition in the cell wall. Cork prevents the loss of water by evaporation. It also protects the interior against entry of harmful microorganisms, mechanical injury and extermes of temperature. cork is light compressible, nonreactive and sufficiently resistant to fire. it is used as stopper for bottles, shock absorption and insulation.