I want to say the 4th option?
Although they have similar symptoms, ways to treat the illnesses are very different. A doctor might find it challenging to diagnose someone with common symptoms because if they choose the wrong course of treatment, the person could end up getting worse.
Differentiation is the process of going from a stem cell to a differentiated, specialized cell.
The answer is stress fracture
Antibiotic resistant is the only thing i can think of that would match this statment
i could be wrong but i hope this helps <span />