The ratio 5 : 3 means for every 5 parts of length, breadth is 3 parts.<br><br>&bull; Length = \(5y\) cm corresponds to 5 parts<br>&bull; 1 part = \(y\) cm<br>&bull; Breadth = 3 parts = \(3y\) cm<br><br>Final Answer: A: \(3y\)