A contributor which is likely to be the cause of U.S. children’s inadequate fitness levels is that: A. children live a sedentary lifestyle.
A sedentary lifestyle can be defined as a type of lifestyle which is typically characterized by an engagement in physical activities that doesn't require or involve the use of energy.
In this context, we can infer and logically deduce that children living a sedentary lifestyle is a contributor which is likely to be the cause of inadequate fitness levels in American children.
Learn more about sedentary lifestyle here: https://brainly.com/question/17429144
#SPJ1