Which principle described by psychologist martin seligman fosters an overall positive attitude by using thinking and behavior techniques to resist negativity?

The correct answer is Learned Optimism.

Martin Seligman developed an area of psychology known as Positive Psychology. One aspect of positive psychology is learned optimism. It is where you teach yourself to think positively instead of negatively, you use certain techniques to alter your thought and behavior patterns so you see optimism in life instead of pessimism.

to prevent people from getting the ebola virus, countries around the world paid to doctors develop a new vaccine. now that the vaccine has been made, doctors will need to experiment on a large number of people to find out if it works safely.

what is the greatest limitation that scientists are dealing with as they try to figure out how to experiment with the ebola vaccine?

meditation is a practice of sitting still and quiet for minutes or even hours. it has been practiced for thousands of years and is even a part of religious practices for some people. carefully controlled, repeated measurements of brain activity have shown that meditation does increase certain chemicals in the brain and even grows the part of the brain that people connect with their current surroundings and activities.

are claims about the effects of meditation most likely scientific or pseudoscientific?

not pseudoscientific, because people have made claims about it but scientific observations have not been made