question:  How are citizens organized into different classes in society?
context: They were such cute synthetic creatures, it was impossible not to love them. But think—we get this house rent-free; I've got my own district with no bosses around; I make my own hours; you'll meet lots of people that stop in at the pound. If I don't want to follow my aptitudes, the only choice is common labor. "They assigned me to it because I liked babies. And because I have a B.S. in biology and an aptitude for dealing with people. Destroying unclaimed units is the smallest part of it. The suburban street wound among the pastel plasticoid cottages that were set approximately two to an acre on the lightly wooded land. With its population legally fixed at three hundred million, most of the country had become one big suburb, dotted with community centers and lined with narrow belts of industrial development. A class-C couple, allowed no children of their own, could get quite attached to a cat-Q-5. When a pet neutroid died, a family was broken with grief; but most couples could endure the death of a cat-Q or a dog-F. Class-C couples were allowed two lesser units or one neutroid. He found himself in Sherman III Community Center—eight blocks of commercial buildings, serving the surrounding suburbs. This could be a ruse to bring a stop to investigations when one animal is found. If allowed to reach age-set or adulthood, such a deviant could be dangerous to its owner or to others. Its replacement-quota of new neutroids was around three hundred animals a month. He tried to estimate how many of July's influx had been K-99s from Bermuda Factory. And there were only eleven empty neutroid cages in his kennel. Only thirty-five of July's Bermuda-K-99s had entered his territory, and they were about equally divided among five pet shops, three of which were in Wylo City. The robot operator, which had on tape the working habits of each Wylo City citizen, began calling numbers.
output:  By an analysis of their genes and heredity
options:  Through random assignment at birth  According to their socioeconomic status  After a lengthy interview with Anthropos upon reaching a specific age-set  By an analysis of their genes and heredity