Answer
We can rank the situations according to the effective current through the regions:
$(a) = (b) = (c) \gt (d)$
Work Step by Step
We can find the effective current directed to the left in each region:
(a)
$-(-7~C/s) = 7~C/s$
(b)
$(3~C/s)-(-4~C/s) = 7~C/s$
(c)
$(2~C/s)-(-5~C/s) = 7~C/s$
(d)
$(6~C/s)+(-1~C/s) = 5~C/s$
We can rank the situations according to the effective current through the regions:
$(a) = (b) = (c) \gt (d)$
