Step 1: Understand the sentence construction.
The sentence is making a comparison, and the phrase “No less remarkable than the invention of nuclear power” is the most appropriate way to express this comparison.
Step 2: Review the options.
- (A) This is the most grammatically correct and effective choice, as it compares the invention of nuclear power to the subsequent effect on international relations.
- (B) "What was as remarkable" changes the meaning of the sentence and introduces unnecessary ambiguity.
- (C) "Inventing nuclear power has been none the less remarkable than" introduces unnecessary complexity and breaks the flow of the sentence.
- (D) "The invention of nuclear power has been no less remarkable as" does not correctly match the comparison structure.
- (E) "The thing that was as remarkable as inventing nuclear power" is awkward and incorrect in this context.
Conclusion:
Option (A) is the best because it maintains a clear and grammatically correct comparison.