Identify the object$-$oriented principle violated in this code.

public class Square $\{$

private double side;

public Square$($double side$)\{$

this. side $=$ side;

$\}$

public double calculateArea$()\{$

return side ${?}^{**}$ side;

$\}$

public String getColor$()\{$

return "Red";

$\}$

$\}$

a$.$ Code to an interface rather than to an implementation.

b$.$ Each class in your application should have only one reason to change.

c$.$ Classes are about behavior and functionality.

d$.$ Encapsulate what varies.

e$.$ None