"she feels happier and more relaxed" after starting kickboxing: this is a MATURE defense mechanism (classic textbook sublimation, as has been said). This question is just plain wrong. It's not displacement, because it's a healthy, socially acceptable outlet that improves her emotional state; punching bags are meant to be punched (thus it is actually NOT neutral). Displacement to an object would be punching a hole in her wall, or breaking her vase (I just like that imagery). Both of those would be better than punching her family, or breaking their car window, which is why it's displacement (unconscious redirection of an emotion to a safer object). However, kickboxing is LITERALLY an example in several psych textbooks for sublimation. Thank you for coming to my TED Talk.

Like others have said, I think sublimation would have been better, but displacement from first aid says that it is, “redirection of emotions or impulses to a neutral person or object” so she’s kicking her family by kicking the bag.

I got so angry at this question. At least this lady had a punching bag

As best as I could tell, it was displacement because the other choices were definitely wrong, not b/c displacement was a good choice. Felt like there were lots of this type of question on this exam.

I think this question was asking about the anger that she expresses toward her family for not helping out more, which is really displacement of her stress related to caring for an ill child. The kickboxing is a second coping mechanism(Sublimation).