In sieve plate column, holes are drilled or punched in sizes ranging from 2.5 to 12 mm (5 mm being widely used). The hole pitch is normally ______________ times the hole diameter to give the required hole area?
(A) 0.5 to 1.5
(B) 2.5 to 4.0
(C) 5 to 10
(D) 10 to 15

