Which area at the tip of a stem is composed of meristematic cells?

The apical meristem is the correct answer because it consists of a group of undifferentiated cells that are capable of continuous division and growth. These meristematic cells are located at the tips of the stems and roots, where they contribute to the elongation of the plant. This type of growth is known as primary growth, which increases the height of the stem and the length of the roots.

The apical meristem plays a crucial role in producing new cells that will eventually differentiate into various tissues, such as xylem and phloem, which are essential for the plant's vascular system. It is the primary site for the growth and development of new shoots and leaves.

In contrast, the pith refers to the central part of the stem and is primarily made up of parenchyma cells, which serve mainly for storage and transport rather than growth. The cork cambium is a type of lateral meristem responsible for producing the outer protective layer and cork cells as part of secondary growth, while the bud scale serves as a protective covering for plant buds, rather than being involved in growth or cell division. Thus, the apical meristem is the only option that aligns with the definition of an area composed specifically of meristem