In a vertical short tube evaporator (Calandria type), the ______________________?

A. Tube dia of 2.5-7.5 cms, tube length of 75-200 cms and cylindrical drum dia of 1-6 metres are
normally used
B. Area of central downtake is equal to 40 to 100% of total cross-sectional area of the
surrounding tube
C. Liquor is inside the tube while the steam is outside the tube
D. All A., B. & C.