Answer:
The inner core
Step-by-step explanation:
The earth's interior is divided into several layers, namely the crust, mantle, and the core. The core is of two types, inner core and the outer core. The mantle also is represented as the upper and the lower mantle.
The inner core is the densest of all the layers of the earth's interior. It is surrounded by the outer core which is liquid in nature. It is comprised of hot, dense elements namely iron (Fe), nickel (Ni) and some siderophile elements. These elements are accumulated in this region due to their higher density. The density of this layer is 13 g/cm³. It has a thickness of about 1200 km forming the smallest layer of the interior of the earth.