The substance that is usually lost by the body during dehydration is-

Correct option is A

The correct answer is (a) Sodium chloride.
· Sodium chloride, commonly known as table salt, is a crucial electrolyte in the human body. It plays a vital role in maintaining fluid balance, nerve transmission, and muscle function.
· During dehydration, the body loses fluids primarily through sweating, vomiting, diarrhoea, or increased urine output. Along with water, these fluids contain dissolved electrolytes, including significant amounts of sodium chloride.
· The loss of sodium chloride can disrupt the balance of electrolytes, leading to symptoms such as cramping, dizziness, and general weakness. Rehydration often requires not only water but also the replacement of electrolytes, which is why sports drinks and oral rehydration solutions typically contain sodium along with other electrolytes.