Oxygen, nitrogen, carbon, hydrogen NOT magnesium
The answer would be letter A. globular cluster. This group of very old stars that are clustered together in a spherical in shape and can contain from 10,000 to several million is called a globular cluster. In our galaxy, there are 150 globular clusters.
Acetylcholine (ACh)
Acetylcholine is an organic chemical that functions in the brain and body of many types of animals as a neurotransmitter.
A pathogen is a disease carrying vector that has the ability to spread using a variety of different mechanisms. A pathogen that is a contagion has the ability to spread through touch. An example of such a pathogen would be the one that results in staph infections.