Obesity is defined as: A. BMI above 35 B. Waist to Height ratio >0.5 C. Waist circumference <88cm for a Caucasian male D. Body Fat >50%

Obesity is typically defined by using the Body Mass Index (BMI). According to the World Health Organization, a BMI greater than or equal to 30 is considered obesity. Therefore, option A is not entirely correct as it states a BMI above 35, which falls under the category of severe obesity.

Option B, Waist to Height ratio >0.5, is a measure often used by health professionals. If your waist circumference is less than half your height, you are usually in the healthy range.

Option C, Waist circumference <88cm for a Caucasian male, is not a correct definition of obesity. In fact, a waist circumference of 102 cm or more in men, regardless of race, is considered obesity.

Option D, Body Fat >50%, is also not a correct definition of obesity. The American Council on Exercise provides ranges for body fat percentages. For men, obesity is typically defined as a body fat percentage of 25% or more. For women, it's 32% or more.

So, none of the options provided perfectly define obesity, but option A and B are somewhat close.