Select the correct answer. Moira purchased and drank one glass of lemonade that cost 50 cents. After finishing the first glass, she was still thirsty.
So, she purchased a second lemonade. She didn't mind spending an additional 50 cents because she needed the drink.
Which economic concept is at play here?
A human capital
B. diversification
C. marginal analysis
D. production

D

Explanation:

Production is a process of combining various material inputs and immaterial inputs in order to make something for consumption. It is the act of creating an output, a good or service which has value and contributes to the utility of individuals.

explanation: d

i believe the correct answer is option b. most eastern european nations joined nato.

though i could be wrong, option d. the eastern european nations were granted complete independence, would be another choice.

hope this ! : )