Question: Which of the following statements regarding Java's Optional class and its usage is true?

A) The Optional class is designed to replace all instances of null in Java applications, ensuring no NullPointerException will occur.
B) The isPresent() method returns true if the Optional contains a value, and the ifPresent() method executes a block of code only if a value is present.
C) Optional can be directly used as a return type for methods that are guaranteed to never return a value.
D) The Optional class is mutable and allows modification of its value after it has been created.