## Core Concept
The Body Mass Index (BMI) is a simple calculation using a person's height and weight to categorize them as underweight, normal weight, overweight, or obese. The formula for BMI is weight in kilograms divided by the square of height in meters. BMI is widely used as a screening tool for health risks associated with excess body fat.

## Why the Correct Answer is Right
To calculate the BMI of a male whose weight is 89 kg and height is 172 cm, we first convert the height into meters. Since 1 meter = 100 cm, 172 cm = 1.72 meters. Then, we apply the BMI formula: BMI = weight (in kg) / height (in meters)² = 89 / (1.72)² = 89 / 2.9584 ≈ 30.1. Therefore, the BMI of this individual is approximately 30.1, which falls into the category of **obesity** according to the World Health Organization's BMI classification.

## Why Each Wrong Option is Incorrect
- **Option A:** Without a specific value, it's impossible to directly refute, but any BMI value not equal to approximately 30.1 would be incorrect for the given parameters.
- **Option B:** Similarly, without a specific value, direct refutation isn't possible, but it would be incorrect if it doesn't match the calculated BMI of approximately 30.1.
- **Option C:** This option is likely incorrect because if option D is correct (BMI of 30), then option C would represent a different BMI category.
- **Option D:** If this option states a BMI of 30, it is essentially correct based on our calculation (BMI ≈ 30.1), making other options with significantly different values incorrect.

## Clinical Pearl / High-Yield Fact
A key point to remember is that BMI categories are as follows: underweight (<18.5), normal weight (18.5-24.9), overweight (25-29.9), and obese (≥30). This classification helps in quickly identifying individuals at risk of obesity-related health issues. ## Correct Answer: D. 30.