Answer:
A) Informative
Step-by-step explanation:
The style, tone, and structure of the passage is informative. It provides information about origin of acupuncture (a medical procedure), regions where it developed, its working mechanism, and then its use in USA. The passage also talks about its possible side-effects, and precautions.
The ominous tone or style foretells or predicts some bad events in the future.
The persuasive style uses claims, arguments and proofs to persuade its audience to believe and follow writer's opinion about a certain topic idea.
Sentimental tone appeals to audience's emotions and sentiments for different purposes.