The factors that made it difficult for Eastern Europe to improve its water quality were outdated sewer systems, raw water quality, worn-out water utilities and unskilled employees.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 />
It’s either B or D I think
Yes, they use and believe in them. We can see this from shuls, the places they use to pray, as the 10 commandments are written and hung up. They also believe in the 10 Commandments since a great historical figure, Moshe was commanded to write them by Hashem, the God. Many people want to follow in Moshe's footsteps so they follow the 10 Commandments.
Hope it helped! :)
