What did Karl Marx believe his version of communism could do for society?

He saw communism as a way to end the cycle of violent unrest in society once and for all.
He predicted communism would make violent revolution a permanent part of life.
He thought communism could bring the benefits of capitalism to everyone.
He wanted communism to strengthen the power of the bourgeoisie.

A is correct.

Explanation: this attitude makes him a humanist. He did not commit any crime (I believe), but he (as many others before him) did not evaluate sufficiently human nature. He believed that humans are better that they are and that is why he believed that they would be able to make "perfect society". Marx died in the 1880s and did not witness times when Communism entered into existence not as a theory, philosophy, doctrine but as regime. He did not witness the way how people put it into existence ...he was a pure theorist.

c.) the country needed a stronger central government.

depends on the age of the teen, many believe by the age of 16 a person should know the strong difference between right and wrong along with the difference between risky and immediate death. swimming with sharks might be dangerous but swimming with sharks while bloody meat is attached to you is just insane. even more if you have no idea what you're doing. however, no matter the age, as long as the person is skilled enough and has the mental and physical capacity to control their actions doing whatever sport they put their mind to is all that matters.