Java: equals and hashCode methods contract

Question

The author of the question says the answer is D, but I wonder why the answer should not be C??

Q: Which statement is true about the code that can fill in the blank?

class Sticker {
  public int hashCode() {
    return 1;
  }
  public boolean equals(Object o) {
    return____________ ;
 }
}

A. It must return false.
B. It must return true.
C. It can return either true or false.
D. None of the above.

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EDIT 1 :

The answer and explanation for it given by the author is following: If two instances of a class have the same hash code, they might or might not be equal. The reverse is not true. If two objects are equal, they must have the same hashcode in order to comply with the contracts of these methods. However, in this case, the answer is none of the above because the method can't simply return true or false. Based on the rules of equals(), if null is passed in, the result must be false. If an object identity is passed in, the result must be true due to reflexivity. As a result, Option D is correct.

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EDIT 2 : May be the author means the following by his explanation given above: I think may be the author wants to say that if we return true from the equals(Object) then there is a possibility that somebody could pass a null in the equals(Object) in which case it will be contradicting the return value true as based on null argument being passed the return value should be false not true . Similarly, if we return false then there is a possibility that a Sticker object identity is passed and then it'll again be contradicting. So basically we can't really fill in the blank with either true or false . May be that was why author said the answer was D.

Answer 1

The author has poorly written the answer options. It is clear from their explanation that their answer choices would be better written as:

A. It should always return false. B. It should always return true. C. Returning true or returning false are always both correct. D. None of the above.

The question might also benefit from a rewrite:

Assuming the code which fills in the blank correctly fulfills the contract of the equals() method, which statement below is always true?

The author has committed two grievous infractions against computer science

1. Keyword violation . 'Return' is a keyword, and it is colossally stupid to use 'return' when you really mean 'return correctly'. Sentence = must attempt to explain pointer logic to a 300-person class of freshmen This particular violation is what makes it so incomprehensible, since a boolean function can obviously return true or false.
2. Boolean logic violation . Booleans can be true or false. Therefore, a function returning a boolean can either always return true, always return false, or sometimes return one and sometimes the other. To give 4 answer choices to a boolean problem is a violation of the nature of booleans. This violation is compounded by the abuse of the keyword 'return', but in and of itself it should be a crime. Sentence = pair-program in C++ with an intern whose only CS education is a React bootcamp