The correct answer is: A. Half brick
A half brick is a piece of a brick cut along the centre of width in such a way that its length is equal to that of full brick. It is used in bricklaying to create a variety of patterns and effects.
A queen closer is a brick that is cut diagonally from corner to corner. It is used to fill in the space between two full bricks at a corner.
A king closer is a brick that is cut diagonally from corner to corner and then cut in half lengthwise. It is used to fill in the space between two full bricks at a corner where the bricks are not aligned.
A bevelled closer is a brick that is cut at an angle on one side. It is used to create a curved or stepped effect in bricklaying.