The correct answer is: A. Transport of water.
Xylem is a complex tissue that transports water and minerals from the roots to the leaves of a plant. It is made up of dead cells that are arranged in long, thin tubes. The walls of these cells are thickened with a substance called lignin, which makes them strong and rigid. This allows the xylem to transport water and minerals up to the leaves, even against the force of gravity.
The xylem is a vital part of the plant’s vascular system. It is responsible for delivering the water and minerals that the plant needs to grow and survive. Without the xylem, the plant would not be able to transport these essential nutrients to its leaves, and it would eventually die.
The other options are incorrect because they are not the primary function of the xylem. Option B, transport of food, is the function of the phloem. Option C, transport of amino acids, is not a function of any plant tissue. Option D, transport of oxygen, is the function of the lungs in animals.