The fact that random variation is always present in any process is called:
Select one:
a. Common cause variability
b. Special cause variability
c. Assignable cause variability
d. Control limit variability

Common cause variation.

Step-by-step explanation: They're two types of variations in economics namely common cause variation and special or assignable cause variation. Common cause variation also referred to as quantifiable variation explains the probabilistically and irregular variation in statistical thinking.