Despite the prevailing notion that the ancient civilization was technologically primitive, new archaeological evidence suggests its engineers possessed a surprisingly ______ understanding of hydraulics, capable of diverting rivers and building complex irrigation systems.

The correct answer to the question "Despite the prevailing notion that the ancient civilization was technologically primitive, new archaeological evidence suggests its engineers possessed a surprisingly ______ understanding of hydraulics, capable of diverting rivers and building complex irrigation systems." is Option B: sophisticated.

The other options — A) rudimentary, C) superficial, D) uninformed — are incorrect for this GRE Exam Prep question. As explained above: The sentence presents a contrast: 'despite the prevailing notion' of primitiveness, the new evidence shows a 'surprisingly' advanced capability. 'Sophisticated' accurately describes a complex and adv…