The population of greenville is currently 50,000 and declines at a rate of 1.2% every year. This models:

Exponential growth.

Exponential logarithm

Exponential decay

Exponential decay. Decay is clear, less. Exponential logarithm is contradictory.

So. the answer is

Exponential decay

Formula: 50000/1.12^years, which could be rewritten as 50,000/e^ (number*years), and so it is exponential.

Declines means getting less in number

So its decay

Choice C