40. An instrument that is inconsistent in measuring a variable would lack: trustworthiness credibility triangulation reliability

Answer: Reliability

Explanation: Reliability is the term that is used in the field of the tool which defines the consistency of the variables and the results. It assures that the readings of the valuers that are obtained can be repeated in future experiments or study. It is also known as the dependability.

Other options are incorrect because trustworthiness and credibility are referred as the validity of the collected values and triangulation is known for tracking. Thus, the correct option is reliability