Why is Earth's outer core hotter than Earth’s oceanic crust?

1 Earth’s oceanic crust is denser than Earth’s outer core is.
2 Earth’s oceanic crust has lava flowing from the mantle.
3 Earth’s outer core has a composition of solid iron and nickel.
4 Earth’s outer core is deeper within Earth than oceanic crust is.

It could be anything, recent improvements in technology/telecommunication/internet have increased the pace of globalization.generally, it has something to do with technology. globalization means that people around the world are brought together through technology which speeds things up. so maybe some of those options could be correct. : )