I would say that the sentence in this paragraph which does not belong is A. Sentence 1.
Nobody really cares if these scientists were on a vacation with their families or not. What is important is stated in the remaining sentences - the age of the tree and its discovery, and not whether or not these people were vacationing.
Answer:
She is never late for school
I trembled at the sound of my own voice, it's all physical, the trembling and the voice.
