What term describes something that is unmanageable or difficult to control?

The term "refractory" is used to describe something that is unmanageable or difficult to control, especially in a medical or behavioral context. When applied to patients, for example, it often refers to conditions that do not respond well to treatment or patients who are resistant to following medical advice. This encapsulates the idea of something being difficult to handle, whether it pertains to behavior, response to treatment, or general manageability.

Other choices do not fit this definition. "Willful" suggests intentionality and stubbornness but does not specifically convey the lack of manageability. "Proofread" refers to the process of reviewing text for errors, and "exacerbation" typically relates to making a condition worse rather than indicating unmanageability. Thus, "refractory" is the most appropriate choice for describing something that is hard to control or manage.