The correct answer is option 'C' - periderm. The cork cambium, cork, and secondary cortex together form the periderm, which is the outer protective layer in the stems and roots of woody plants. Let's understand each component in detail:

1. Cork Cambium:
- The cork cambium is a lateral meristem, a type of actively dividing tissue, located in the outer bark of woody plants.
- It is responsible for the production of cork cells towards the outside and secondary cortex cells towards the inside.
- The cork cambium originates from the secondary meristematic activity of the vascular cambium.
- Its main function is to replace the epidermis with a protective layer, the cork.

2. Cork:
- Cork is a protective tissue formed by the cork cambium.
- It is composed of dead cells that are rich in suberin, a waxy substance that makes them impermeable to water and gases.
- The cork cells are arranged in compact layers, which provide protection against physical damage, water loss, and invasion by pathogens.
- Cork cells also have air-filled spaces called lenticels, which allow gas exchange between the inner tissues and the outside environment.

3. Secondary Cortex:
- The secondary cortex is a layer of tissue formed by the cork cambium towards the inside.
- It is composed of living cells, which function in storage and support.
- The secondary cortex helps in the transportation of water and nutrients through its parenchyma cells.
- In some plants, the secondary cortex may also contain secretory cells that produce resins, gums, or latex.

4. Periderm:
- The periderm is the collective term for the cork cambium, cork, and secondary cortex.
- It is an outer protective layer that replaces the epidermis in older stems and roots of woody plants.
- The periderm provides protection against mechanical damage, water loss, and pathogens.
- As the stem or root expands in girth, the periderm replaces the epidermis, which becomes stretched and eventually ruptures.
- The periderm is continuous and remains intact as the plant grows, unlike the epidermis, which is constantly sloughed off and replaced.

In conclusion, the cork cambium, cork, and secondary cortex collectively form the periderm, which is the outer protective layer in woody plants. The periderm is essential for the plant's survival and provides protection against various environmental stresses.