B because your blood goes to organs and give the body nutrients.
Answer:
Magnesium, calcium, phosphorous, sulfur these are essential nutrients for plants. These are required in trace quantity but are very important for plant life. Point A. will be correct answer.
Explanation:
As in B. starch n cellulose are composed of only carbon, oxygen and hydrogen.
As in C. These elements are not required on special occasion but are necessary throughout plant life.
As in D. C H N O is the primary component plants need but these secondary nutrients are equally necessary for growth n structure of plant.
<u><em>So answer A. Is the correct option.</em></u>
Calcium plays the most important role in structure formation of plants. Also act as messenger molecule in signaling. Deficiency of calcium caused wilting , weakened stem and ultimately death of plant.
Magnesium is the key element in chlorophyll molecule. It is necessary for chlorophyll formation.
Sulfur is another very important element in plant life, it is necessary for protein synthesis in plants.
Phosphorous plays an important role in process of cell devision , photosynthesis and respiration.
Potassium is very crucial in gaseous exchange ,it operates the opening and closing of stomata.
Pollution can come from both natural sources and human activities depending on the type of pollutant.
<h3>What is pollution?</h3>
It is the release of substances into the environment to the extent that the well-being of plants, animals, and humans starts getting affected.
Substances that are released into the environment to the extent that they start affecting the organisms in the environment negatively are known as pollutants.
Pollutants can come from natural sources or as a result of human activities.
For example pollutants such as oxides of sulfur, methane, carbon dioxide, etc. can come from natural processes such as volcanic eruptions, activities of microbes, etc.
Pollutants such as oxides of carbon and sulfur can also be generated as a result of human activities such as the burning of coal, technological inventions, etc.
More on pollution can be found here: brainly.com/question/23857736
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Pi and sigma bonds
Pi is double bonds and sigma is single bonds
