Suppose $50\textbackslash\%$ of $x$ equals $30\textbackslash\%$ of $y$. What percentage of $y$ is $x$ ? (adapted from 2020 AMC 8, Question 15) 
选项为:A:$$40$$  B:$$60$$  C:$$80$$  D:$120$  E:$$200$$  请回答其中一个选项.