**Core Concept**
Dental fluorosis is a condition characterized by changes in the appearance of tooth enamel due to excessive exposure to fluoride during tooth development. It is a milder form of skeletal fluorosis, which affects the bones and joints. The severity of dental fluorosis is directly related to the level of fluoride exposure.

**Why the Correct Answer is Right**
The correct answer is associated with the concept of "optimal fluoride levels." Dental fluorosis is not associated with skeletal fluorosis when the fluoride levels are within the optimal range for oral health, which is typically between 0.005 and 0.07 milligrams per liter of water. At these levels, fluoride promotes tooth enamel formation and prevents tooth decay without causing skeletal fluorosis. The optimal fluoride level is crucial in preventing dental fluorosis without increasing the risk of skeletal fluorosis.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify the correct fluoride level range. Excessive fluoride exposure above the optimal range can lead to both dental and skeletal fluorosis.
**Option B:** This option is incorrect because it does not consider the concept of optimal fluoride levels. Even within the optimal range, dental fluorosis can still occur due to other factors such as genetic predisposition or excessive fluoride intake through non-water sources.
**Option C:** This option is incorrect because it implies that dental fluorosis is always associated with skeletal fluorosis. While both conditions are related to fluoride exposure, they can occur independently depending on the fluoride level and individual factors.

**Clinical Pearl / High-Yield Fact**
To remember the optimal fluoride level range, use the mnemonic "5-7": 0.005 to 0.07 milligrams per liter. This range is crucial in preventing dental fluorosis while minimizing the risk of skeletal fluorosis.

**Correct Answer: A. Optimal fluoride levels between 0.005 and 0.07 mg/L prevent dental fluorosis without increasing the risk of skeletal fluorosis.**