Final answer:
The word 'impressively' best emphasizes the complexity of the paper sculptures as it conveys the intricate details and the skill involved in creating such art forms.
Step-by-step explanation:
The word that most effectively emphasizes the complexity of the paper sculptures would be 'impressively'. This choice conveys the intricate details and the skill required to create such complex art forms. While 'terrifically' and 'superbly' also suggest positive qualities, they do not specifically highlight the intricate or complex nature of the sculptures. On the other hand, 'impressively' directly relates to the observer's reaction to the complexity of the sculptures.
Choice C, impressively, most effectively emphasizes the complexity of the paper sculptures. This word conveys a sense of awe and wonder, suggesting that the sculptures are remarkably intricate and impressive. For example, if someone were to describe a paper sculpture as 'impressively complex,' it would indicate that the sculpture is intricately designed and visually stunning.