Pick up the correct statement from the following:
(A) Bull's trench kiln a trench excavated in ground
(B) Hoffman's kiln is constructed over ground
(C) Tunnel Kiln is constructed as a tunnel
(D) All the above
(A) Bull's trench kiln a trench excavated in ground
(B) Hoffman's kiln is constructed over ground
(C) Tunnel Kiln is constructed as a tunnel
(D) All the above