It is important to send a resume in an envelope this size in order to avoid folding it. A folded resume looks unprofessional and careless. As caring about details and being presentable are important qualities in a candidate, being unable to exhibit them can affect your changes of getting hired.
The reason why resumes should not be folded goes being making it neater and more presentable to employers' eyes when opening the envelope. Folding a resume may cause scanning issues. Many employers choose to scan hardcopy resumes to save them as electronic ones. Folding may make a part of the resume less visible to the scanner, making the electronic copy flawed. As we know, the main purpose of a resume is to get someone a job. Any mistake or problem with it may cost that person his/her opportunity.
C- Ambivalent. She says in the story that she would rather lose her family then marry him. She later changes her feelings on this topic, and they get married. Hope this helps!