If we change from two to four passes on the tube side of a given shell-and-tube exchanger (the same.

If we change from two to four passes on the tube side of a
given shell-and-tube exchanger (the same shell diameter and number of tubes)
with the same tube flow rate, the tube-side velocity in turbulent flow will:

(a) remain the same (b) increase by 40%

(c) increase by 74% (d) increase by a factor of 2

(e) increase by a factor of 4 (f ) increase by a factor of 8