Question

Which revision of the sentence is now properly punctuated? The peripheral nervous system—which is a network of nerves extending from your brain and spinal cord to all parts of your body carries signals back and forth. The peripheral nervous system (which is a network of nerves) extending from your brain and spinal cord to all parts of your body carries signals back and forth. The peripheral nervous system which is a network of nerves extending from your brain and spinal cord to all parts of your body carries signals back and forth. The peripheral nervous system—which is a network of nerves extending from your brain and spinal cord to all parts of your body—carries signals back and forth.

Answer 1

"The peripheral nervous system—which is a network of nerves extending from your brain and spinal cord to all parts of your body—carries signals back and forth." is correct.