Answer: The battle of Gettysburg!
Because you have been teached this in 5th grade, And the paragraph matches the answer!
Glad to help :)
-liyah❤
<span>The Marginal Rate of Substitution refers to the rate the consumer is willing to trade for another good to maintain the level of satisfaction. It is described by ratio of prices. Maximum satisfaction is achieved when trade offs between two goods are equal. </span>