The correct answer is C. sodium.
Rock salt is a mineral composed of sodium chloride (NaCl). It is the most common salt in the world and is used in a variety of applications, including food, water treatment, and road de-icing.
Potassium is a mineral that is found in many foods, including fruits, vegetables, and meat. It is an essential nutrient for human health and is involved in a variety of bodily functions, including muscle contraction, nerve function, and blood pressure regulation.
Magnesium is a mineral that is found in many foods, including nuts, seeds, and whole grains. It is an essential nutrient for human health and is involved in a variety of bodily functions, including muscle contraction, nerve function, and energy production.
Iron is a mineral that is found in many foods, including meat, poultry, fish, and beans. It is an essential nutrient for human health and is involved in a variety of bodily functions, including blood production, oxygen transport, and energy production.