Answer:
The answer is "The threat to internal validity is mortality".
Explanation:
It signifies that while in terms of your study, persons were "morning." It usually signifies when people leave the studies. There will be only likely if indeed the experiment lasts a long period that it'll be a substantial danger to validity and reliability because the chance for drops increases. Eight content validity risks are history, maturity, instrument, test, choice, average regress, human engagement, and mortality.