**Core Concept**
The World Health Organization (WHO) defines body mass index (BMI) categories to classify individuals based on their weight status. BMI is calculated as the individual's weight in kilograms divided by the square of their height in meters.

**Why the Correct Answer is Right**
BMI is a widely used measurement to assess weight status. According to the WHO, an individual with a BMI between 25.0 and 29.9 is considered overweight. This range indicates a higher risk of chronic diseases, such as diabetes, cardiovascular disease, and certain cancers. The exact cut-off points are 25.0 for overweight and 30.0 for obesity. The correct answer range accounts for this distinction.

**Why Each Wrong Option is Incorrect**
**Option A:** This range is too low, as it does not capture the full spectrum of overweight individuals. A BMI of 24.0 is actually within the normal weight range.
**Option B:** This range is slightly too low, as it does not include the full overweight category. A BMI of 27.9 is still within the overweight range.
**Option C:** This range is slightly too low, as it does not include the upper end of the overweight category. A BMI of 28.9 is still within the overweight range.

**Clinical Pearl / High-Yield Fact**
The BMI categories defined by the WHO are: underweight (BMI < 18.5), normal weight (BMI = 18.5-24.9), overweight (BMI = 25-29.9), and obesity (BMI ≥ 30). It's essential to remember that BMI is a calculated value and does not account for muscle mass or body composition.

**✓ Correct Answer: D. 25.0 - 29.9**