A 70-year-old woman has a small-bowel fistula with output of 1.5 L/d. Replacement of daily losses should be handled using the fluid solution that has the following composition in mEq/L.

**Core Concept**
The management of a small-bowel fistula involves replacing the daily fluid losses to prevent dehydration and electrolyte imbalances. This requires a balanced electrolyte solution that mimics the composition of intestinal fluid.

**Why the Correct Answer is Right**
The correct answer involves a solution that is isosmotic to intestinal fluid, with a sodium concentration of around 90 mEq/L, a potassium concentration of 20-30 mEq/L, and a chloride concentration of approximately 80 mEq/L. This solution helps to replace the lost fluids and electrolytes, preventing hypovolemia and electrolyte imbalances.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option does not provide the correct sodium concentration, which is too high and may lead to hypernatremia.
* **Option B:** This option does not provide the correct potassium concentration, which is too low and may lead to hypokalemia.
* **Option C:** This option does not provide the correct chloride concentration, which is too high and may lead to hyperchloremia.

**Clinical Pearl / High-Yield Fact**
In managing a small-bowel fistula, it's essential to remember that the fluid replacement solution should be isosmotic to intestinal fluid to prevent fluid shifts and electrolyte imbalances.

**Correct Answer: C.**