Answer:
D. reversal of identity
Step-by-step explanation:
Twist endings are unexpected endings in literatute, films, plays etc. Everything becomes clear and is shown to be contrary to the thing expected.
It is usually said that there are five basic reversals.
1) reversal of identity - a person revealed to be somebody else
2) reversal of motive - character's motivation is the opposite of previously assumed
3) reversal of perception - things aren't the way character thought they were
4) reversal of fortune - a mistake, misunderstanding or a coincidence changes the character's situation
5) reversal of fulfilment - one character stops another from acheiving the goal in very last minutes
Now, this particular case is most likely an example of reversal of identity - a person thought to be someone else is revealed to be close to the main character. We can gind example of this when King Oedipus realizes that his lover is actually his mother.