How do I call values from this table?

Hi. I asked this a few weeks ago but I'll post it again with some added information.

I have a table that stores questions and four possible answers, of which only one is correct. I found that I could create a table as follows and I found this code from a lua helpsite not specific to ROBLOX. I can apparently read values from this table by print(GeneralKnowledge[1][2]) to print "London" however this doesn't seem to work correctly.

GeneralKnowledge = {}
for i = 1, 4 do
    GeneralKnowledge[i] = { 0,0,0,0,0 }
end 
GeneralKnowledge[1] = {"What is 2+2?","2","3","4","i"}
GeneralKnowledge[2] = {"What is the capital city of the UK?", "London","Belfast","Dublin","Cardiff"}

Can anyone help? There is the following error. print(GeneralKnowledge[1][2]):1: attempt to index global 'GeneralKnowledge' (a nil value)

The table is stored within a script in the startergui.

Thanks.