Hey All,
I was asked by PM to answer this one, so here I am!
This question involves modifiers and subject-verb agreement, and is pretty straight forward from there.
83. Although it claims to delve into political issues, television can be superficial such as when each of the three major networks broadcast exactly the same statement from a political candidate.
(A) superficial such as when each of the three major networks
PROBLEM: The subject here is "each" (of the three major networks is just a modifier of each). Each is singular, so it can't work with the verb "broadcast". Also, we need a comma before "such as". This is a complicated issue involving the notion of essential versus non-essential modifiers. This sentence makes sense without the modifier (i.e. "television can be superficial"), so we would call the modifier after it NON-essential. We put commas before non-essential modifiers.
An example of an essential use of such as: "Words such as "ye" used to denote old-time language are based on an incorrect understandings of older scripts."
Notice how this sentence doesn't make sense without the modifier... "Words...are approximations based on incorrect understandings..." doesn't make any sense. The "such as "ye"" is essential.
(B) superficial, as can sometimes occur if all of the three major networks
PROBLEM: "When" and "if" don't mean the same thing. This occurs WHEN all three major networks broadcast the same thing, not IF they do. Also, the doubling of "can" is pretty ugly, because it's unclear what the "sometimes occurring" is referring to.
(C) superficial if the three major networks all
PROBLEM: This is even worse then above, but the same issue. It's not that television can be superficial if the networks do something, it's that television becomes superficial WHEN they do that thing.
(D) superficial whenever each of the three major networks
PROBLEM: Same as A, "each" is singular here.
(E) superficial, as when the three major networks each
ANSWER: Okay. I know what you're thinking...there's an "each" here, too. Why should this one be plural when the others are singular. Well, there's a big difference. When you have "each" as the subject (followed by a prepositional phrase, as in A and D), it's singular. When you use "each" AFTER a plural noun with which it is in apposition (that's right, each is a MODIFIER of "three major networks"), each IS NOT the subject, but an adjective modifying whatever comes before it, in this case "three major networks", which is plural, and matches "broadcast".
Phew!
-tommy