What is the difference between a read-only variable and a static variable when defined within a class?: A) A read-only variable must be initialized in the constructor, while a static variable can remain uninitialized. B) A readonly variable requires a class instance, while a static variable does not. C) A read-only variable can be accessed in any method, while a static variable can only be accessed in a static method. D) All of the above are differences between read-only and static variables when defined within a class