The first thing that jumped out at me when I read the question was "it". What is it? Where is its antecendant? Is it Germany, nuclear power or energy? It's not clear.

This signalled to me that this was a pronoun sc correction problem, and that the best solution would have to fix the ambiguity related to it. In particular, the correct answer should make it clear that 'it' is actually energy derived from nuclear power within the respective country (i.e., Germany)

I then scanned the answer choices and the only one that clearly fixes this ambiguity is C. D is tempting, but was the nuclear power derived from energy produced in Germany? We're not told anything about where it was produced - perhaps it was produced in France?!

IMO C, was quite clearly the correct answer. All I had to rely on for this was the pronoun error.

p.s., I'm not familiar with the distinction between compared vs whereas. How could I have immediately knocked out compared using this rule?

Thanks