Option D is the one that shows the correct punctuation of the sentence. This option shows that: Hypnosis, likewise, is another promising but unproven treatment.
In the sentence shown above, the word "likewise" is the transition word that must be enclosed in commas. This is because it is an adverb that promotes the meaning of similarities between terms,
More information about adverbs is in the link:
https://brainly.com/question/8554630