My StringValue Isn't Changing?

Hey, so I'm making an application center for my group I'm making, but in my script a StringValue is supposed to change so that the server can recognize if the player got the correct answer or not, but my StringValue just isn't changing. My script:

(Client Button)

script.Parent.MouseButton1Click:Connect(function()
	local current = script.Parent.Parent.Selected.Value
	if current == "None" then
		script.Parent.Text = "X"
		script.Parent.Parent.Selected.Value = "D"
	elseif current ~= "D" then
		local switch = current.."B"
		script.Parent.Parent:FindFirstChild(switch).Text = ""
		script.Parent.Text = "X"
		script.Parent.Parent.Selected.Value = "D"
	end
end)

(Server)

script.Parent.Parent.Parent.Submit.END.MouseButton1Click:Connect(function()
	local q = script.Parent.Parent.Parent.Q1.Selected.Value
	local a = script.Parent.Parent.Parent.Q1.Right.Value
	if a == q then
		script.Parent.Text =  " ?"
		script.Parent.Parent.Right.Value = script.Parent.Parent.Right.Value + 1
	else
		script.Parent.Text = "X"
	end
end)

Thanks in advance.

I would change the way that you are checking to see if a question was right.

Local script that is inside the button, here is some pseudocode

script.Parent.MouseButton1Click:Connect(function()
	local current = script.Parent.Parent.Selected.Value
	if theCurrentIsAtLeastValid then
		local res = -- use a remote function to see if the answer is correct

		if the server told us it was the correct answer then
			-- tell the user they got is correct
		else
			-- tell the user they got it incorrect
		end
	else
		-- tell the user their input is not valid
	end
end)

Server script in ServerScriptService

function remoteFunction.OnServerInvoke(player, question, answer)
	if the answer is the correct response to the question then
		return true
	else
		return false
	end
end