Keeping the Peace by giving it into an aggressors demands is known as what?

Appeasement

Explanation:

"Appeasement" is the process of giving the aggressor what it demands in order to retain peace and order. A perfect example of this is the "Munich Agreement" on September 30, 1938. The Great Britain avoided getting into war with Germany by engaging in this diplomatic strategy that it will not interfere with the plan of Hitler to annex Sudetenland. So, in this case, it gave Germans what they demanded. This is the reason why the conquests made by Hitler were not made known to the public in Britain.

by 1880, germany had more rail lines than great britain and russia.

letter a is the answer