What are examples indicate memory problems as a result of forgetting?

The question is incomplete and the complete question is :

Which of the following examples indicate memory problems as a result of forgetting?

1 Jane cannot find her keys.

2 Bill cannot answer a question on an exam after studying for it.

3 Mike thought he remembered his boss telling staff about a policy change, but in actuality, the conversation occurred among staff.

4 Annabel could not remember the ending to a movie she had seen three years ago.

5 After hearing news that his high school friend was arrested for drunk driving, John falsely remembered a time his friend was drunk in class.

6 After being hit in the head with a basketball, Mark couldn't recall how he got to the game.

Option 1, 2, 4

Explanation:

These are the examples that shows that the person is not able to remember things even after it belongs to them.

There can be multiple reasons because of which the people cannot remember things.

There can be some medical conditions due to which the person cannot remember things. Example: Dementia, short term memory loss, seizure in brain et cetera.

So there are some example of the things which shows that the person is forgetting things.