Answer: A) the sentence refers to the lifespan and how it's effected by vaccinations.
Explanation:
What grade is this so can look in my old social studies textbook. I think I did the same exact assignment
To show you've done research on the subject, and it can also make it so if you copy and pasted it can show you didn't commit plagiarism.
Example: Why citing is important
It's important to cite sources you used in your research for several reasons: To show your reader you've done proper research by listing sources you used to get your information. To be a responsible scholar by giving credit to other researchers and acknowledging their ideas.Nov 13, 2019
Overview - Citing sources - LibGuides at MIT Libraries
https://libguides.mit.edu › citing
Hope this helps, if not, comment below please
