Population, health, and the environment[citation needed] (PHE) is an approach to human development that integrates family planning and health with conservation efforts to seek synergistic successes for greater conservation and human welfare outcomes than single sector approaches. There is a deep relationship between population, health and environment. Those subjects are not only related to each other but also to other important aspects that are very necessary for keeping PHE in a close-knit relationship.
I would say a because he ran too much but that would be just me I think he hurt his knee from running too much more exercise but probably just aggravate his condition I could be wrong but this is what I think