Answer:
B
Explanation:
Control a heavily desired or needed supply/luxury that is only known to exist in 1 part of the world, and you have a monopoly on it, and you can control the price to your liking, and other countries can't do anything about it, so if they want it, they'll have to pay the price you set.
The most common last name in the United States is John or Smith as most surnames originated from professions of the person.
The factors that made it difficult for Eastern Europe to improve its water quality were outdated sewer systems, raw water quality, worn-out water utilities and unskilled employees. So we can say that four options given in the question fits the bill perfectly. These basic infrastructural reasons were responsible for being a hurdle towards improving the water quality. <span />