Career Field: ways of categorizing different types of jobs based on common similarities.
Occupation: An occupation is a type of job with the same job duties.
Career: an occupation undertaken for a significant period of a person's life and with opportunities for progress.
Job: a paid position of regular employment.
Them because it is a non-gendered plural. Sisters is plural, as would be brother+sisters.
I believe it’s A, sorry if it’s incorrect