All else being equal a study with which of the following err

All else being equal, a study with which of the following error ranges would be the most reliable? A. plusminus 12 percentage points B. plusminus 9 percentage points c. plusminus 3 percentage points D. plusminus 6 percentage points

+-3 will be most reliable as it will give least error because 3 is smallest and +-3 error will be least