Which statement best explains why earth’s outer core is in liquid form? the iron-nickel alloy melts due to hot temperatures. the outer core has a tarry consistency. this region is less dense when compared to the mantle. this region is under extreme pressure from the weight of other layers.

 The iron-nickel alloy melts due to hot temperatures.

Explanation:

Earth's outer core is composed of  fluid layer that is about 2400 km thick and primarily composed of iron and nickel alloy. It lies above the solid inner core and below the mantle. The core of the earth is like a furnace. It exhibit intense heat and pressure which keeps the iron-nickel alloy in the molten state in the core region.

its temperature is increasing. this causes molecular vibrations to increase.