There have been many estimates for when the earth's inner core was formed, but scientists have used new data which indicate that the Earth's inner core was formed 1-1.5 billion years ago as it 'froze' from the surrounding molten iron outer core.A. There have been many estimates for when the earth's inner core was formed, but scientists have used new data which indicate that the Earth's inner core was formed 1-1.5 billion years ago as it 'froze' from the surrounding molten iron outer core
B. There has been many estimates for when the earth's inner core was formed, but scientists who have used new data indicating that the Earth's inner core was formed 1-1.5 billion years ago as it 'froze' from the surrounding molten iron outer core
C. There has been many estimates which indicates that the Earth's inner core was formed 1-1.5 billion years ago, but scientists have used new data for when the earth's inner core was formed as it 'froze' from the surrounding molten iron outer core
D. There have been many estimates, but scientists have used new data for when the earth's inner core was formed as it 'froze' from the surrounding molten iron outer core which indicates that the Earth's inner core was formed 1-1.5 billion years ago
E. There have been many estimates for when the earth's inner core was formed, but scientists have used new data which indicates that the Earth's inner core was formed 1-1.5 billion years ago as it 'froze' from the surrounding molten iron outer core