Answer:
b. dissociative amnesia.
Step-by-step explanation:
Dissociative amnesia -
It is a type of disorder , where it becomes difficult to remember some important and personal information , which occurs due to some type of stress , is referred to as dissociative amnesia.
In this case the person forgets about his or her horrifying event , but it slightly conscious and scared to do the particular task unknowingly .
Hence , from the scenario of the question , Jack is suffering from dissociative amnesia.