How can I record the names of a set of files?

People often set a variable using a wildcard expression to record a list of filenames. For example, if you define datasets like this:

datasets=seasonal/*.csv

you can display the files' names later using:

for filename in $datasets; do echo $filename; done

This saves typing and makes errors less likely.

If you run these two commands in your home directory, how many lines of output will they print?

files=seasonal/*.csv
for f in $files; do echo $f; done

None: since files is defined on a separate line, it has no value in the second line.
One: the word "files".
Four: the names of all four seasonal data files.