**Core Concept**
Mummification of the umbilical cord is a post-mortem change that occurs due to drying and shrinkage of the cord tissue, which is influenced by environmental conditions and the time elapsed since birth. This process is a result of the loss of moisture and the action of microorganisms.

**Why the Correct Answer is Right**
Mummification of the umbilical cord typically occurs within 2-5 days after birth. The rate of mummification is affected by the ambient temperature, humidity, and the presence of microorganisms. In a warm and dry environment, the cord dries out rapidly, leading to mummification. In contrast, a moist environment slows down this process. The correct answer reflects the average time frame for mummification to occur under standard conditions.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is too short, as mummification usually takes longer than 1 day to occur.
**Option B:** While mummification can occur within 5 days, option C is more accurate, as it represents the average time frame for this process to occur.
**Option D:** This option is too long, as mummification typically occurs before 7-10 days after birth.

**Clinical Pearl / High-Yield Fact**
When examining a newborn, it's essential to note the condition of the umbilical cord stump, as changes in its appearance can provide clues about the time elapsed since birth. A well-dried and shrunk cord stump is a normal finding, while a cord that is still moist or bleeding may indicate a more recent birth.

**Correct Answer: C. 2-5 days**