Answer #4 is from an autobiography, an autobiography is a piece written by someone, about themselves, so in this case, answer 4 is the only one with a pronoun relating to oneself.
The answer is d. because collective is not as knid of verb it's a kind of noun.
To be financially responsible means to be able to live within your means. Therefore, someone who is financially responsible can anticipate his expenditures, and ensure he has enough money to meet his needs. A financially responsible person also avoids entering into contracts that will stress his financial situation, such as very large loans. Finally, a financially responsible person is able to save money in order to be prepared for future unfortunate events.
The answer would be 6.0 x 10^3