Isn't there a problem with E?. Doesn't it miss a semicolon? Two independent clauses should be separated by a semicolon and not a comma?

Technically speaking, there's never a problem with the OA, right?

The first clause in the sentence isn't independent because of the "when." Take a simple example: "Tim ate pancakes." Perfectly honorable independent clause. But "When Tim ate pancakes," is not independent - you can probably feel that the construction is incomplete, that the writer is withholding something important. The reason is that the "when" communicates that another action is happening at the same time, and we need that action in order to have a complete sentence. "When Tim ate pancakes, his soul left his body and smiled upon him from heaven." There's no semicolon here, and we don't need one, because we have one dependent clause beginning with "when" and one independent clause beginning with "his soul."

The takeaway: if a clause begins with a word like "when" or "although" that clause is not going to be independent. (If you're into terminology, those words are called "subordinating conjunctions." Also, "subordinating conjunctions" might make an excellent name for a rock band. Or maybe a polka band?)

I hope that helps!
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