"His clothing is particular."
Translation:Seine Kleidung ist speziell.
'Seine' is used because the German word for clothing (Kleidung) is a feminine word thus you have to add the feminine suffix 'e' to the word Sein to form Seine. (Because 'his' precedes the feminine 'clothing')
The English translation is simply wrong,it makes no sense whatsoever. Wahrscheinlich, we were told means probable, likely, so that's wrong too. All in all its a shocking piece of education.