What is false about applying aggregate functions to an aggregate?

The selected answer is correct because when using aggregates in OutSystems, the output does not always include all attributes of the source entities. Instead, only the specified attributes and the additional aggregation columns are included in the output. This means that any attributes that are not explicitly selected or are set to be excluded (indicated by a greyed-out column) will not appear in the final result set of the aggregate.

In this way, when you create an aggregate and select specific columns for output, any attributes that are not marked for inclusion will not contribute to the aggregate's result, which is particularly important for performance and clarity. Therefore, the expectation that all attributes will be present in the output contradicts the functioning of aggregates.

Other statements are accurate: multiple aggregation functions can be applied, various functions can indeed be used on integer data types, and greyed-out columns will not be in the output. This understanding is crucial for effectively utilizing data retrieved and displayed through aggregates in OutSystems applications.