distinguish between x and y
distinguish x from y
are the two correct usages of idoms.
A)pronounced alterations in mood, which may be frequent and occasionally severe without their constituting a clinical illness, from bipolar disorders
Wrong. It follows the x from y idomatic form but "their" spoils it.
B)bipolar disorders and pronounced alterations in mood, occurring frequently and occasionally severely, without constituting a clinical illness
Wrong
C) pronounced alterations in mood, perhaps frequent and occasionally severe without constituting a clinical illness, and bipolar disorders
wrong. wrong idiomatic usage.
D)between pronounced alterations in mood, which may be frequent and occasionally severe without constituting a clinical illness, from bipolar disorders.
wrong. Wrong idiomatic usage.
E)between pronounced alterations in mood, which may be frequent and occasionally severe without constituting a clinical illness, and bipolar disorders.
Correct. distinguish between x and y