How are salt levels maintained in the body

Sodium levels in the body are partly controlled by a hormone called aldosterone.

Explanation: Aldosterone levels tell the kidneys when to hold sodium in the body instead of passing it (through urine.) Small amounts of sodium are also lost through the skin when you sweat.

the element that provides strength to the exoskeletons of clams and oysters is phosphorus. this is so because calcium carbonate is the main component in the shells.

explanation:

i believe the answer would be b. hope it : )