The business analyst creates one table by concatenating and joining several source tables.

TheDensityvalue in the Data Model Viewer provides a measure of how "dense" or "sparse" a field is in terms of data completeness. A higher density value means fewer nulls, while a lower value indicatesmore nulls. By checking the density value for each field, the business analyst can determine the percentage of non-null values, which is critical for understanding data quality and completeness.

Key Concepts:

Density Value: This is a measure in Qlik Sense that indicates the proportion of non-null values in a field. A field with a high density is mostly populated, while a lower density indicates a high proportion of null values.

Data Model Viewer: This tool allows analysts to inspect the structure and quality of data fields, including metrics such as density.

Why the Other Options Are Less Suitable:

B. Preview Panel: While the Preview Panel shows sample data, it does not provide a comprehensive measure of null values and is more suited for a quick glance rather than detailed analysis.

C. Tags fields with $null: This would show if the field contains any nulls, but it wouldn’t quantify the level of nulls.

D. Subset Ratio: The subset ratio compares values across related tables, not null values within individual fields.

References for Qlik Sense Business Analyst:

Data Quality in Qlik Sense: Using theDensityvalue is the best way to assess the proportion of null values in a field, making it ideal for the business analyst to understand the completeness of the data.

Thus,Ais the correct answer because the density value provides the required insight into the level of nulls in each field.