Final answer:
The central idea of the passage is that the Egyptian pyramids, particularly those on the Giza plateau, are astoundingly large, representing remarkable architectural and engineering accomplishments.
Step-by-step explanation:
The central idea of this passage is B. The Egyptian pyramids are amazingly large. The passage emphasizes the grand scale and engineering marvel of the Giza pyramids. Descriptions of the Great Pyramid of Khufu, the step pyramid of Djoser, and the unmatched size and weight of the stone blocks used, highlight the incredible size and construction efforts of these ancient monuments. The reference to the Great Pyramid being the tallest man-made structure in the world for almost four thousand years and being part of the Seven Wonders of the ancient world further underlines the awe-inspiring scale of these structures.