Final answer:
A BMI of <18.5 kg/m² classifies a person as underweight. BMI is a way to measure body weight relative to height and helps determine if a person is underweight, normal weight, overweight, or obese.
Step-by-step explanation:
The classification for a BMI (Body Mass Index) of < 18.5 kg/m² is considered underweight. BMI is a relative measure of body weight compared to overall height. A normal BMI ranges from 18-24.9 kg/m², indicating normal weight, while a BMI of 25-29.9 kg/m² is considered overweight. A person with a BMI >30 kg/m² is classified as obese, and those with a BMI ≥ 40 kg/m² are considered to have morbid obesity, especially if they also have obesity-related health problems.