A cable is constructed by soldering together four identical aluminum wires in parallel. Initially, each wire has length L and radius r, and the resistance of any one of the wires is R0. The cable is then uniformly stretched so that its length becomes 1.5L and the radius of each individual wire becomes 0.80r. What is the resistance of the stretched cable expressed in terms of R0?
(a) 0.47R0
(b) 2.3R0
(c) 0.56R0
(d) 0.59R0