Two Horizontal Pipes Are the Same Length, but Pipe B $Q = \frac { \Delta V } { \Delta t }$

Multiple Choice

Two horizontal pipes are the same length, but pipe B has twice the diameter of pipe A. Water undergoes viscous flow in both pipes, subject to the same pressure difference across the lengths of the pipes. If the flow rate in pipe A is $Q = \frac { \Delta V } { \Delta t }$ what is the flow rate in pipe B ?

A) 4 Q
B) 8 Q
C) $Q \sqrt { 2 }$
D) 16 Q
E) 2 Q