**Core Concept:** The question is about the storage duration of expressed breast milk, which is crucial information for mothers who need to store their milk for later feeding.

**Why the Correct Answer is Right:** The correct answer is based on the guidelines provided by the American Academy of Pediatrics (AAP) and the World Health Organization (WHO). According to these organizations, expressed breast milk can be safely stored in a refrigerator for up to 48 hours. This allows mothers ample time to express and store milk for their infants to consume later.

**Why Each Wrong Option is Incorrect:**

A. 24 Hours: This option is incorrect due to the potential for bacterial growth, causing contamination and potential harm to the infant.
B. 72 Hours: This option is also incorrect, as the risk of bacterial growth increases significantly over 48 hours, making it unsafe for infants to consume.
C. 48 Hours: This option is correct, aligning with the recommendations from AAP and WHO.
D. 96 Hours: This option is incorrect because the risk of bacterial growth remains high even after 48 hours, making it unsafe for infants.

**Clinical Pearl / High-Yield Fact:** To ensure the safety and quality of stored breast milk, it is essential for mothers to follow proper storage techniques, including using airtight containers, labeling the milk with the date and time of expression, and maintaining the temperature below 4°C. This helps prevent bacterial growth and maintains the nutritional value of the milk.

**Correct Answer:** **48 Hours** - Expressed breast milk can be safely stored in a refrigerator for up to 48 hours, according to guidelines from the American Academy of Pediatrics and the World Health Organization.