What tissue type covers the entire plant?

Epidermal tissue is the correct answer because it serves as the protective outer layer of various parts of a plant, including leaves, stems, and roots. This tissue is crucial for safeguarding the inner tissues from environmental stressors such as pathogens, excessive moisture loss, and mechanical damage. The epidermis often includes specialized structures such as cuticles, which help reduce water loss, and stomata, which facilitate gas exchange.

In contrast, mesophyll tissue is primarily found within leaves and is involved in photosynthesis, making it a specific internal tissue type. Vascular tissue, which includes xylem and phloem, is responsible for the transportation of water, nutrients, and food throughout the plant, but does not cover the plant. Ground tissue is involved in various functions such as storage, support, and photosynthesis, but again, it does not serve as the outer covering. Therefore, while other tissue types have important roles, only epidermal tissue consistently forms the external layer across the plant.