Which of the following is made up of dead cells?

Cork cambium undergoes periclinal division and cuts off thick walled suberised dead cork cells towards outside and it cuts off thin walled living cells i.e., phelloderm on an inner side.

Xylem parenchyma is the only living component of xylem. Phloem is a living, complex permanent tissue where only Bast fibres are dead. Collenchyma is called as living, mechanical, simple permanent tissue.