What were some of the challenges of traveling by ship across the Atlantic Ocean?

the effect of the ming leaders banning ships with more than two masts was that there was no further construction of ships masts, because there was a surplus. ming emperors disallowed foreign exploration

the real answer is b

soviet influence spread across eastern europe sharply during and after wwii. the soviet armies liberated the countries in eastern europe and occupied them from the germans as they were forced to retreat towards germany.