Average bases can be included as a condition in an adjustment rule for averages. Here's why:

Average Bases: Average bases refer to the specific wage types you want to include in an average calculation. Adjustment rules allow you to specify conditions that filter which wage types should contribute to a particular average.

Why the other options are less likely:

Cumulation rule: Cumulation rules control how values are accumulated across time, but they don't directly define conditions for adjusting averages.

Time unit: This is relevant to average calculations but wouldn't be a condition within the adjustment rule itself. The adjustment rule might use different time units for its calculations.

PCR for average formula: PCRs can be used to define the calculation logic behind averages, but they're not directly used as conditions within adjustment rules.

How do adjustments work for averages?

Adjustment rules allow you to refine average calculations by:

Filtering Wage Types: Specifying which wage types should be included or excluded from the average.

Conditionally Applying Rules: Define conditions that determine when a specific adjustment should take place.