The tone in the above passage is objective.
Answer: Option A
Explanation:
The passage gives facts or a factual description of vaccines. This means that what has been said about vaccines is true. Objective tone is used in a passage when the writer wants to describe or give facts related to something. Objective tone is not a biased opinion of the writer but presents the facts in a neutral way as they are.
Objective tone in a sentence or passage does not make use of emotive words or personal pronouns so that the sentence can provide an actual description and not the opinion of the writer.