Identify the defining characteristic in the following nursing diagnosis statement: Altered speech related to recent neurological disturbance as evidenced by inability to speak in complete sentences:

A. "Inability to speak in complete sentences": In a nursing diagnosis, the defining characteristic is the observable or measurable cue that demonstrates the existence of the problem. The inability to speak in complete sentences is the evidence that the client exhibits altered speech, providing a concrete manifestation of the diagnosis. B. "Recent neurological disturbance": This phrase represents the related factor or etiology in the nursing diagnosis, explaining the probable cause of the altered speech. While it helps link the problem to its source, it is not a defining characteristic because it is not an observable symptom or behavior. C. "Altered speech": This is the actual nursing diagnosis or problem statement, not the defining characteristic. It identifies the health issue requiring nursing intervention but does not specify how the problem presents in the client. D. "As evidenced by": This phrase functions as a connector between the problem and the defining characteristic. It signals that the following statement will describe the observable manifestation but is not itself a defining characteristic.