**Core Concept**
Deciduous mandibular lateral incisors are a type of permanent tooth that develops from the dental lamina. The process of crown completion in teeth involves the formation of the enamel, dentin, and pulp, which are essential for the structural integrity and function of the tooth.

**Why the Correct Answer is Right**
The crown completion of deciduous mandibular lateral incisors typically occurs between 6-7 years of age. This process involves the formation of the enamel, which is the hardest substance in the human body, and the dentin, which provides the structural support for the tooth. The pulp, located at the center of the tooth, contains the nerves and blood vessels necessary for tooth development and maintenance. The timing of crown completion is crucial for the proper eruption and function of the tooth.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the crown completion of deciduous mandibular lateral incisors does not typically occur before the age of 5 years.
**Option B:** This option is incorrect because the crown completion of deciduous mandibular lateral incisors does not typically occur after the age of 8 years.
**Option C:** This option is incorrect because the crown completion of deciduous mandibular lateral incisors does not typically occur simultaneously with the eruption of the tooth.

**Clinical Pearl / High-Yield Fact**
It is essential for pediatric dentists and general practitioners to be aware of the normal timeline for crown completion of deciduous teeth, as this information can aid in the diagnosis and treatment of dental abnormalities and developmental delays.

**Correct Answer: C. Between 6-7 years of age.**