1. The domain of Products Manufactured would be counting numbers. The best choice here might be ... 4) whole numbers
The Cost of Production can have any positive value (not always limited to only 2 decimal places), so its range is likely best described by ... 2) positive real numbers
2. The independent variable of the described function is "the number of observed vehicles in a specified time interval." If we assume only whole numbers of vehicles are observed, then the best choice for the domain appears to be the open-ended set of non-negative values ... 4) {0, 1, 2, 3, ...}
Since we don't know what the function C does, except that it produces something called "the rate of traffic through an intersection", we really can't say what its range might be. The choice that allows the most possiblities* is the open-ended set ... 1) {..., -2, -1, 0, 1, 2, 3, ...}
_____ * you might argue that traffic flow is always positive. I woud say that depends on your reference direction, and that it might be positive for part of the day and negative for another part. The choices here seem to include some of limited range. Whether that applies depends on the details of C(n), which we are not told. I would argue that C(n) might have a range that includes real numbers (limited only by the number of cars that can go through an intersection in a time period of interest--which might be quite large).
