A.
They disagreed about who should control certain cities and regions.
I know Columbus was one... Sorry, that's all I know.
The religious institution demonstrate simplicity by encouraging people to follow the testimony of simplicity and to have a simple lifestyle.
<u>Explanation:</u>
The religious institutions of the Christianity religion state that simplicity is the theme of the religion. People should have a simple living style and should only focus on the things which are important for them in their lives.
They should not pay much attention to the things which are not very important in life. According to St. Thomas, god is infinitely simple and so should be his people. Thus religion encourage the people to follow the testimony of simplicity.
The leader who was in the USA was Jimmy carter. in Britain the prime minister was James Callaghan. However this is because the detente collapsed in 1979 after soviet invasion of Afghanistan.
As per the question however, in the 1980's the USA leader was Reagan and great Britain was Thatcher Margaret.