Which term is associated with behavior that is overly concerned with details?

The term "punctilious" is the correct choice as it refers to someone who is very attentive to detail, often to the point of being overly precise or meticulous about rules and minor details. This word captures the essence of being excessively concerned with small aspects, which aligns perfectly with the behavior described in the question.

In contrast, "rampant" refers to something that is widespread or unchecked, often used in a negative context to describe an uncontrolled situation. "Rancorous" denotes a deep-seated resentment or bitterness, typically used to describe feelings rather than behaviors related to attention to detail. "Renounce" means to formally reject or give up something, which does not relate to the behavior of being detail-oriented. Therefore, "punctilious" stands out as the only term that accurately describes an individual who is overly concerned with details.