Answer C

@HannahNg, Let's look at (C). (C) says, "cannot satisfy economic needs by means of interactions with family members and close friends" The problem with (C) is that love and friendship (interactions with family members and close friends) are not necessary to satisfy economic needs, but it is still possible that interactions with family members and close friends could satisfy economic needs (what if the people are running a family business or something where they're benefitting economically through their interactions with their family and close friends?). In this example, you could have economic interactions with family and close friends, which could thereby satisfy economic needs. For this reason, (C) does not logically complete the argument, so it's out. Does this make sense? Let us know if you have any other questions!