I don't understand question 4
can someone explain why the answer is type 1 error?
Let me address the fourth question in the exam to you in more explanatory details:
You are taking a pregnancy test. The null hypothesis of this test is: I am not pregnant (null hypothesis). In reality, you are not pregnant (null hypothesis is true), but the test says you are (rejected the true null hypothesis). Which type of error occurred?
Here you can say that the test has made a type I error that actually makes a rejection to the true null hypothesis.
Another way to disscuss:
This lady is truly not preganant. For some reasons, she sought medical advice to test if she is preganant or not. She brought the pregnancy test and tested herself. The test result was she is preganant. So, here she will handle her subsequent life as a pregnant, but truly she is not. So, we can say that she is falsely preganant (i.e., falsely positive according to the test).
Hope you got the point.