Answer: Maturation
Explanation:
Maturation threat is defined as the process that impact internal system by threatening it. Time is the major factor in this process that impacts the growth and changes of people in terms of cognition and physical factors.It can also influence the activity of person without requirement of treatment .
Other options are incorrect because history, test or selection are not the factors that can impact the internal validity of the person as a threat.Thus, the correct option is maturation threat.
