Among the following, which elements are considered essential nutrients for plant life?

The answer is accurate because the elements listed in the first choice—carbon (C), oxygen (O), hydrogen (H), nitrogen (N), phosphorus (P), and potassium (K)—are fundamental to plant nutrition.

Carbon, oxygen, and hydrogen are the primary building blocks of organic molecules and are obtained mainly from air and water. Nitrogen is crucial for the synthesis of amino acids, proteins, and nucleic acids, making it essential for growth and development. Phosphorus plays a critical role in energy transfer within the plant, particularly in the form of ATP (adenosine triphosphate), and it is also vital for root development and flowering. Potassium is important for regulating various physiological processes, such as water uptake and enzyme activation, making these six elements fundamental to plant life.

The other options include elements that play important roles in plant growth and development but are not classified as essential nutrients in the same manner. Copper (Cu) and cobalt (Co) are micronutrients, but they are not part of the primary macronutrients needed in larger quantities. The micronutrients such as iron (Fe), zinc (Zn), manganese (Mn), calcium (Ca), and magnesium (Mg) are indeed vital for many biochemical processes but