Why do we designate one of the candidate keys of a relation to be the primary key?

Shaniya has misspelled a scientific name in her biology report. she needs to correct it, but she has no access to a computer. she plans to use the word app on her phone without an office 365 subscription. can shaniya correct her mistake? why or why not? yes, she can navigate the window and do simple editing. yes, she can use this application for free and navigate the window. no, her document is “read-only,” so she cannot navigate the window. no, her application has limited features and she cannot access the documen