Miss Ophelia may not be right cause you didn't list choices.
The answer would be “energy”.
The sentence says that Caseyis a “bundle of energy”, meaning she is mostly very energetic and moves a lot. However, something happened to make her feel the opposite way (because of the high fever), or lethargic.
The antonym of “lethargic” (which means very sluggish) is “energy”.
They can give you more resources if you need help, like websites or games for the topic you are learning. They can teach by using hands-on, visual, or note-taking ways. Play games of the topic you just learned before a test, etc.
Calm-placid
enthusiastic-zealous
palpable-tangible
scruples-morals
I hope this helps! Have a great day!
