If your version of WeBWorK is newer, use parserCheckboxList.pl:
https://github.com/openwebwork/pg/blob/main/macros/parsers/parserCheckboxList.pl
And options are kept in the original order unless you encase them in an additional pair of brackets.
If you have to use the older tool, you can use the makeLast method to force the options to be displayed in a desired order:
https://webwork.maa.org/wiki/MultipleSelectProblems