Answer: The correct answer is- C) Companion cells.
Phloem tissue is a complex conducting tissue that is present in the vascular plants and responsible for the transport of organic compound such as carbohydrates and proteins from leaves to the rest part of the plant.
The various components of phloem tissue are- Sieve element, Companion cells, phloem parenchyma, phloem fiber.
Companion cells are specialized cells ( present in association of sieve element) that perform various metabolic reactions and responsible for cellular activities. They help in loading and unloading of carbohydrate into sieve element.