When we want to heat a stream of liquid by Steam, and the steam may condense into liquid. Then which of the following is best suited?

• A. Steam on the side with the fins
• B. Steam on the side with the fins and condensate drainage
• C. Steam on the side with the fins and a brush to remove the condensate film from surface
• D. Steam on the tube with the fins on inner surface of the tube passing through a pool of cooling liquid