Which term describes an action done with great care and thoroughness?

The term that describes an action done with great care and thoroughness is "painstaking." This word embodies a commitment to meticulousness and diligence, indicating that someone is putting in a significant amount of effort and attention to detail in their work. In many professional settings, especially in law enforcement and other critical fields, performing tasks painstakingly ensures accuracy and quality, which are essential for effective outcomes.

The other options denote qualities that oppose thoroughness. "Careless" implies a lack of attention or consideration, often leading to mistakes. "Sloppy" suggests a hasty or unorganized approach that overlooks important details, which can compromise the integrity of one's work. "Rushed" indicates a hurried effort, where speed takes precedence over quality, potentially resulting in errors and misjudgments. Thus, "painstaking" stands out as the most appropriate choice to convey the idea of deliberate and careful action.