The Cranial Nervous System nerves connect the brain to the eyes, mouth, ears and other parts of the head. The Autonomic Nervous System nerves connect the central nervous system to the lungs, heart, stomach, intestines, bladder and sex organs. The branch of medicine that studies the nervous system is called neurology. The nervous system, essentially the body’s electrical wiring, is a complex collection of nerves and specialized cells known as neurons that transmit signals between different parts of the body. Neurons signal to other cells through fibers called axons. Chemicals called neurotransmitters are released at gaps called synapses. These communications take only a fraction of a millisecond. Sensory neurons respond to stimuli such as light and sound.
He's actually a biologist who specializes in organic chemistry. But since that's not in the answer choices, i'd recommend putting Scientist or Dermatologist.
The planets and other heavenly bodies are attracted towards the earth by the earth's gravity. The pull which is formed by the gravity of earth holds the objects near the earth surfaces. The planets and atmosphere is also kept around the earth's surface by the gravity.
