Which alphabet letter is a question?

You have to fill the below given grid in a manner that every row and column contains the digits 1 to 6. Also, make sure that the squares that are connected with each other must contains the same digit.

What does the following BrainBat signifies?

ABCDEFGHIJKLMNOPQRSTUVWYZ

QQQQQQQQQQQQQQQQQQQQQQQQQ.

It has five wheels, though often think four, You cannot use it without that one more, You can put things in it, you can strap things on top, You can't find it in the market, but you can still go shop. What is it?

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?

You need to pick one entry from pot A and one from pot B to have a perfect match. Can you do it?

What breaks yet never falls, and what falls yet never breaks?

Can you make four (4) nines (9) equal 100?

What goes up but never comes down?

What question can you never answer yes to?