Final answer:
The correct answer is option c. The plant adaptation responsible for the development of primary growth is the c) vascular system, which allows the elongation of the plant's roots and shoots by transporting nutrients and water and supporting increased height and size.
Step-by-step explanation:
Plant Adaptation Responsible for Primary Growth
Among the various adaptations that plants have evolved for life on land, primary growth is a significant developmental process that enables plants to increase in length. The adaptation that is responsible for the development of primary growth is the c) vascular system. The vascular system, consisting of vascular tissues, allows the transport of water and nutrients throughout the plant and supports its ability to grow taller.
Primary growth is facilitated by the presence of apical meristems located at the tips of roots and shoots, which divide to promote vertical growth. This process is different from secondary growth, which involves the increase in girth through the development of additional vascular tissue and is marked by the presence of lignin.
While lignin does play a crucial role in strengthening the plant's structure and enabling it to support larger masses, it is not the direct cause of primary growth; hence, option a) lignin is not the correct answer. The b) cuticle is an adaptation that helps prevent water loss but does not contribute directly to growth. Lastly, d) development of seeds refers to the reproductive adaptation in plants that is separate from the mechanism of primary growth.
Thus, the correct option is c) vascular system, as it is directly associated with the primary growth in plants, enabling them to increase in height and size above ground.