What is the primary cause of hydroplaning / aquaplaning (akvaplaninq) while driving in wet weather?

1. Driving with high tyre pressure on dry asphalt.
2. A wedge of water building up in front of and beneath the tyre faster than the tread can evacuate it, causing the tyre to lose contact with the road surface.
3. Overheating of the brake discs.
4. Engine oil leaking onto the windshield.