Pick up the correct statement regarding the centre line method of estimating a building

Q. Pick up the correct statement regarding the centre line method of estimating a building

A.            Product of the centre line of the walls and area of cross-section of any item, gives total quantity of the item

B.            The centre line is worked out separately for different sections of walls of a building

C.            The centre line length is reduced by half the layer of main wall joining the partition wall

D.            All the above

Answer: All the above