Final answer:
Water loss in the body occurs through both the skin and respiratory tract (option A) and through urination and feces (option B).
Step-by-step explanation:
Water is lost from the body through various processes, and the correct answer is: D) both a and b.
Water loss occurs through several avenues:
1. Skin: Water evaporates from the skin's surface through a process known as insensible perspiration, especially when the body is warm.
2. Respiratory Tract: Water is lost during breathing as water vapor in exhaled air.
3. Urination: The excretion of urine by the kidneys involves the removal of water from the body.
4. Feces: While the primary role of the large intestine is to reabsorb water from undigested food, water is still lost in the form of feces.
Therefore, water loss in the body occurs through both the skin and respiratory tract (option A) and through urination and feces (option B).