The correct answer is option 1 - Trees. Trees are a type of plant that are very tall and have hard and thick brown stems. Trees are characterized by their woody stems, which provide support and stability. The thick stem of a tree is called a trunk, and it is made up of layers of bark, sapwood, and heartwood. The hard and thick stem of a tree allows it to grow tall and strong, providing support for the branches and leaves. Trees are found in various habitats, including forests, woodlands, and even urban areas. They play a crucial role in providing oxygen, shade, and habitats for numerous species of animals and birds.