Designated Language help

[raedf]

Dear All;
im new here in the fourm and i filled my application for 175 visa class(GSM). in the final step they ask me if you have Designated Language.
my mother tounge is arabic so i wantt o claim 5 point for that so is it spossible if i got letter from my university that all the study was in english i can cliam it or what evidence i need to got to apporoved my language???

thanks all