Final answer:
Jackie's intrusive memories suggest unsuccessful repression, which is when anxiety-causing memories are involuntarily blocked from consciousness but can resurface and cause symptoms.answer is option c.
Step-by-step explanation:
Jackie's experience with intrusive memories of an emotionally traumatic event that she has been trying to forget is evidence of unsuccessful C) repression. Repression is a defense mechanism where anxiety-causing memories are blocked from consciousness. These repressed memories may continue to cause symptoms in other areas, despite being removed from conscious awareness.
Semantic encoding, the spacing effect, and rehearsal are not applicable here. Semantic encoding refers to the input of words and their meaning, leading to better retention when the material is personally relevant due to the self-reference effect. The spacing effect deals with the distribution of learning over time, and rehearsal is the conscious repetition of information. In Jackie's case, the issue is not with encoding or the method of learning, but rather the inability to keep the memory out of consciousness.