**Core Concept**
The use of Oral Rehydration Solution (ORS) combined with Zinc supplementation is a well-established strategy for the treatment of acute diarrhea, particularly in children. This combination addresses both the fluid and electrolyte losses associated with diarrhea, as well as the underlying immune response that contributes to the duration of the illness.

**Why the Correct Answer is Right**
The addition of Zinc to ORS has been shown to significantly reduce the duration of acute diarrhea by enhancing the immune response and improving gut integrity. Zinc plays a crucial role in maintaining the integrity of the intestinal mucosa and regulating the immune system, which helps to reduce the severity and duration of diarrhea. Studies have consistently demonstrated that Zinc supplementation, when combined with ORS, can lead to a shorter duration of diarrhea and a reduced risk of subsequent episodes.

**Why Each Wrong Option is Incorrect**
**Option A:** Reduces infection - While Zinc does have antimicrobial properties, the primary benefit of ORS plus Zinc in the context of acute diarrhea is to reduce the duration of the illness, not to prevent infection.
**Option B:** Antispasmodic - ORS and Zinc do not have antispasmodic effects, and this is not a relevant mechanism in the treatment of acute diarrhea.
**Option D:** Enhance sodium absorption - While ORS is designed to replenish electrolytes, including sodium, the primary benefit of adding Zinc is not to enhance sodium absorption.

**Clinical Pearl / High-Yield Fact**
The World Health Organization recommends the use of ORS plus Zinc for the treatment of acute diarrhea in children, as it has been shown to reduce the duration of illness and the risk of subsequent episodes.

**✓ Correct Answer: C. Reduces duration of diarrhea**