A. One of the axis must contain a dimension.
B. One of the axis must contain an aggregated measure.
C. The reference line must be created on a continuous axis.
D. The reference line must be paired with a date field.
Explanation:
In Tableau, to create a reference line, one of the axes in the view must contain an aggregated measure. Reference lines are typically used to add context or additional information to the data in a view, and they are often based on some form of aggregate such as the average, median, sum, etc., of a measure.