A or c might be the answer
Sadly, even after that water is found, only some of it's clean and safe enough to drink
If you get the app everything is free, and the app is free
Mercy Hospital admits 200 patients a day, including about 25 who are unable to pay for their own medical care.
This sentence creates an image in your mind to illustrate how many people a day the hospital sees.
If this is MLA format, in-text citations only require the author and the page number. if no author exists, then you provide the title and the page number. if there is no author and no page number, you simply give the title.
assuming the author is starks, the page is 97, and the title is "animals"--you only have to put (Starks 97) in parentheses. the author and the page is enough information for someone to access your source.