I believe the answer of an epidural hematoma is correct because of the following:
a. They are usually arterial bleeds vs usually venous bleeds (subdural)
b. Because they are in the space between the outermost layer and the skull, there is no place for the blood to go which can cause a rapid increase in ICP
c. Although subdural hematomas have a higher mortality rate than epidural hematomas, I think that because there are also minor subdural hematomas that can occur without issue, the rapid increase in ICP that occurs in epidural hematomas raise a more emergent issue. (But of course both need immediate medical attention, one is just more emergent than the other)
Please let me know if this has been helpful. I wish you luck in your studies!