The downcomer design and the residence time in the downcomer is almost same for seive plate and bubble cap columns.
Weir length for a bubble cap plate is the same as that for the seive plate.
Weir height for a bubble cap plate column is the same as that for a seive plate column.
Weir height in case of a bubble cap plate ranges from 50 to 150 mm and is higher than the seive plate.
✅ The correct answer is option C.