Question

when is a chart legend used

Answer 1

Chart legends are used whenever we are comparing multiple sets of data. A legend helps describe each part that make up a chart. It is most frequently situated on the right-hand side of the chart or graph and can occasionally be enclosed by a border and mostly used to compare data.

Answer 2

the answer is C. on my paper at least

so the answer is

C.Whenever you are comparing multiple sets of data

good luck