I think the best answer will be c because everyone knows how he spends time
Answer:
it gives it more character and emotion

I don't recommend using the first person pronoun in an argumentative essay. Unless your instructor suggests that you do so, omit it from the assignment because your writing will read better without it.
Answer:
I would say "Twenty dollars a week doesn’t go far. Expenses had been greater than she had calculated. They always are."
Explanation:
In this answer, it explicitly says " Expenses had been greater than she had calculated. They always are." which infers that by saying "they always are", would imply she never makes enough money to be financially fit.