Condensing Film Co-Efficient for Steam on Horizontal Tubes Ranges from 5000

Condensing film co-efficient for steam on horizontal tubes ranges from 5000 to 15000 Kcal/hr.m².°C. Condensation of vapor is carried out inside the tube in a shell and tube heat exchanger, when the

A) Higher condensing film co-efficient is desired
B) Condensate is corrosive in nature
C) Lower pressure drop through the exchanger is desired
D) Temperature of the incoming vapor is very high