The correct answer is option (a). Parent material
The soil horizon refers to distinct layers of the soils, which are parallel to one another, but have a different composition from the layer present above and below to it.
The soil horizon can be divided into four different layers. First one is organic layer, which is the topmost layer, below this layer second layer of topsoil is present. Below top soil, subsoil is present. Below subsoil, the bottom most horizon parent material is present.
Your question is really vague, but when I typed it in, I found this website with people answering the same question: https://studyandanswers.com/biology/question20660094
Answer:
Brain cells are very sensitive to a lack of oxygen. Some brain cells start dying less than 5 minutes after their oxygen supply disappears. As a result, brain hypoxia can rapidly cause severe brain damage or death.
Explanation:
Other symptoms can include: hallucinations and delusions; increased agitation and confusion; depression and other mood disorders; personality changes, such as irritability and a reduced threshold for frustration; and an inability to focus or concentrate.
Cell theory is one of the foundations of biology. The observation of Robert Hooke,Anton Van Leeuewenhoek,Matthias Schleiden,Theodor Schwann,Rudolf Virchow, and others led to the devolepment of the cell theory.
