Why is the inner core Earth’s most dense region? (a) The inner core is made of mostly iron, which is very dense. (b) Dense material sank toward Earth’s center when Earth was molten. (c) Pressure packs...

Why is the inner core Earth’s most dense region?

(a) The inner core is made of mostly iron, which is very dense.

(b) Dense material sank toward Earth’s center when Earth was molten.

(c) Pressure packs the atoms in the inner core tightly together.

(d) all of these