Answer:
C. The city population increases by 1000 every year.
Step-by-step explanation:
A linear function of time means that over time, the city's population also changes and it is like a relationship between time and the growth. A and B only says that during that one year, it increased by 1000 so it is a temporary change and no growth was mentioned. C and shows that every year, there is a steady change (1000 per year) so it is a linear function. D's increase would be too drastic as the 10% increase would increase so it would not be a steady line so it is not a linear function.
