I would like to know how to include any math symbols in the dropdown list of embedded (cloze) answers. I have tried, but while I am able to upload in the question text, I am not able to upload it in the dropdown list.(in the dropdown list, i am able to upload only ordinary text)
Is there a special software/ font that I must use?
The largest set of symbols is unicode - try for example http://rishida.net/scripts/uniview/ , click some symbol and copy the presented unicode symbol from output field to your cloze answer.
One way is to use HTML entities like α or β - moodle will change them to unicode characters when you click first<> (turn editor off to source view) and back: α and β
Which artifact?
http://moodle.org/mod/forum/discuss.php?d=123806
artifact is the behavior as evidenced in the test site http://korpelainen.net/plugindemo/ and discussed here http://moodle.org/mod/forum/discuss.php?d=123806&parent=542973
I posted some comments about failure of using images (or fallback images in TeX filter, asciimathml or latexmathml) in dropdown lists (IE,Opera,Safari) to http://moodle.org/mod/forum/discuss.php?d=123806 - FF rules here again...
About adding any unicode characters to these drop down lists we have that Enrique's unicode picker plugin (Insert Special Character) for HTMLArea http://moodle.org/mod/forum/discuss.php?d=20864 and I am planning to create an extended unicode picker or a modified virtual keyboard plugin for tinymce later too (August) - there is already one such (russian version) available but it should probably be a "moodle version"...
The main problem with unicode is that all fonts and all browsers do not show all unicode characters...but you can't use images instead of missing characters either for IE,Opera or Safari in dropdown lists...