______ is the value of the sieve opening through which exactly 50 % of the resin volume passes.

______ is the value of the sieve opening through which exactly 50 % of

1.	______ is the value of the sieve opening through which exactly 50 % of the resin volume passes.
A.	Mean diameter
B.	Effective size
C.	Harmonic mean size
D.	Uniformity coefficient
Answer» B. Effective size