The correct answer is: A. The Archaean Rock system.
The Archaean Rock system is the oldest rock system in the world. It is made up of igneous and metamorphic rocks that were formed over 4 billion years ago. The Archaean Rock system is found in many parts of the world, including Australia, Canada, Greenland, and Russia.
The Zircons Rock system is a type of igneous rock that is found in many parts of the world. It is made up of zircon, a mineral that is very resistant to weathering. The Zircons Rock system is thought to have formed between 4.4 and 4.0 billion years ago.
The Primitive Rock system is a type of metamorphic rock that is found in many parts of the world. It is made up of rocks that were originally igneous or sedimentary rocks that have been changed by heat and pressure. The Primitive Rock system is thought to have formed between 4.0 and 3.8 billion years ago.
None of these is the correct answer because it is not a rock system.