ASAP PLEASE HELP

Which example from the text develops the idea that it remains a mystery as to how the Egyptians moved and stacked the stones they used to build the pyramids?
“The Great Pyramid weighed approximately 5,750,00 tons. A draft horse can pull four tons in its own…”

“Perhaps they used systems or ramps, ropes and plain, old-fashioned elbow grease…”

“A team from the French Institute for Oriental Archaeology discovered a unique ramp system…”

“But the ancient Egyptians didn’t use horses, and they certainly didn’t have pickup trucks.”