**Core Concept**
The primary dentition, also known as baby teeth, starts erupting when a child is around 6 months old and continues until they are 3 years old. However, the first permanent teeth to appear mark the beginning of the mixed dentition stage, which is a transitional phase between the primary and permanent dentition.

**Why the Correct Answer is Right**
The first permanent teeth to appear are typically the first molars, which erupt around the age of 6 years. This is because the primary second molars are lost, and the roots of the primary second molars resorb, making way for the permanent first molars to erupt. The eruption of permanent first molars is a significant milestone in a child's dental development.

**Why Each Wrong Option is Incorrect**
**Option B:** Premolars, also known as bicuspids, erupt after the first molars, typically between the ages of 10 to 12 years.
**Option C:** Incisors, both central and lateral, erupt before the first molars, typically between the ages of 6 to 8 years.
**Option D:** Canines, also known as cuspids, erupt after the first molars, typically between the ages of 9 to 12 years.

**Clinical Pearl / High-Yield Fact**
It's essential for pediatricians and dentists to keep track of a child's dental development to provide timely guidance and interventions. The eruption of permanent teeth can be affected by various factors, including genetics, nutrition, and oral health habits.

✓ Correct Answer: A. Molor First permanent teeth to appear are the first molars.