The cortex of a herbaceous stem is made up of

The cortex is the region of a plant stem located between the epidermis and the vascular bundles. In a herbaceous (non-woody) stem, the cortex is composed of two main tissue types:

• Collenchyma occupies the outer part of the cortex, just beneath the epidermis. It consists of living cells with unevenly thickened cell walls that provide flexible mechanical support, allowing the young stem to bend without breaking.
• Parenchyma makes up the bulk of the inner cortex. These are thin-walled, living cells with large vacuoles. They function in storage of food, water, and waste products, and they also carry out photosynthesis when chloroplasts are present (chlorenchyma).

Xylem is a vascular tissue found in the stele (vascular cylinder), not in the cortex. Sclerenchyma, which consists of dead cells with uniformly thickened lignified walls, is characteristic of woody stems and mature tissues rather than the cortex of a typical herbaceous stem.

The correct combination is therefore parenchyma and collenchyma, as these are the ground tissues that together constitute the cortex of a herbaceous stem.