pretty sure they want the "If a patient is in pain, _they_ can use the call button to alert a nurse." which is bullcrap but, what can you do
Third person plural pronoun is THEY.
If you want to create a possessive pronoun out of that one, that would be THEIRS.
Possessive pronouns, as the name itself says, determine some kind of possession. For example:
Is this books yours? - No, it's theirs.
I would probably go with C
"The Gift of the Magi" remains a popular story for its sentimental narrative, with moral lessons around Christmas time. With timeless themes of youth, love, relationships, money struggles and Christmas it remains universally popular.
Yes i agree with this but you should definitely explain in more details on how peoples health will improve