COUNT(field_name) tallies only those rows that contain a value; it ignores all null values.

Option A: True - The COUNT(field_name) function in SQL counts only those rows where the specified field (column) contains a non-null value. It does not count rows where the field is null. Therefore, rows with null values in the specified field are ignored in the count. Conclusion:
The statement "COUNT(field_name) tallies only those rows that contain a value; it ignores all null values" is Option A: True. Hence, the correct answer is True.