B as it's not government regulations, technology or funding
The nervous system includes the brain, spinal cord, and a complex network of neurons. This system is responsible for sending, receiving, and interpreting information from all parts of the body. The nervous system monitors and coordinates internal organ function and responds to changes in the external environment.
• Neurons are the basic unit of the nervous system. All cells of the nervous system are comprised of neurons. Neurons contain nerve processes which are "finger-like" projections that extend from the nerve cell body. The nerve processes consist of axons and dendrites which are able to conduct and transmit signals.
• The brain is the control center of the body. One of these furrows, the medial longitudinal fissure, divides the brain into left and right hemispheres. Covering the brain is a protective layer of connective tissue known as the meninges.
• The spinal cord runs down the center of the protective spinal column extending from the neck to the lower back. Spinal cord nerves transmit information from body organs and external stimuli to the brain and send information from the brain to other areas of the body.
Answer: Hereditary carrier or carrier
A hereditary carrier is a person or an organism that has inherited a recessive allele. Alleles are pairs or series of genes on a chromosome that determines hereditary characteristics. Carriers have the genetic trait but do not show the trait or show symptoms of any disease.
Geologist Alfred Wegner noticed similar rocks & fossils remains were found on Continents which seemed to fit together. He called saw that it was the result of Continental drift and Pangea. Some evidence of the Drift was Rock evidence- Mountain ranges, Glacial scares, Location of coal deposits, ETC..
People couldn't image how the Earth could be millions of years ago. But the 1960's evidence would prove Continental Drift is TRUE and .. the story continues (as all good science!)
Continental drift means that continents move away from each other or separated.