What is the name of the dried-up river channel in the Fayoum governorate, a UNESCO World Heritage site, that contains the world's most important fossil deposit of early whales with vestigial hind limbs?

• A Wadi al-Natrun
• B Wadi al-Gimal
• C Wadi al-Hammamat
• D Wadi al-Hitan (Valley of the Whales) ✓

Wadi al-Hitan, a UNESCO World Heritage site in the Fayoum governorate, preserves hundreds of fossilized skeletons of Archaeoceti — early whales that still possessed vestigial hind limbs — providing the clearest paleontological evidence of the evolutionary transition from land mammals to fully aquatic whales.