I am a non EU citizen currently holding a valid resident permit of Luxembourg. As there is no UK visa application center in Luxembourg I have to apply from UK visa application center in Brussels, Belgium. In the online uk visa application form question
What permission do you have to be in Belgium?
What answer suits my case more as I am currently a resident of Luxembourg so I have authority to move freely among schengen states including Belgium and my resident permit in Luxembourg is till year 2020
(a) To choose "I have temporary visa" and mention that it ends at 2020
(b) or to choose "I do not have a visa and I am not a permanent resident" and state that I actually holds a resident permit of Luxembourg thus need no visa for travel to Belgium as both countries are in schengen region