<prompt> Body mass index BMI is a ratio of body weight to ?HeightSquare root of heightSquare of heightCube of height  <response>: Ans. is c i.e., Square of height Body mass index Body mass index BMI is a simple index of weight for height that is commonly used to classify underweight, overweight and obesity in adults. It is defined as the weight in kilograms divided by the squire of height in metres. 