SOLUTION
Given the question in the image, the following are steps to solve the problem.
Step 1: Write out the function that defines the cost of the condominium
![\begin{gathered} f(x)=1200x+2400 \\ \text{where x }represents\text{ number of months} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/6qnf9m6vlc15w4ufs83afjc5teea0zprqq.png)
Step 2: Calculate how much Karen pays for the condominium after living there for 12 months by substituting 12 for x in the function defined above:
![\begin{gathered} f(x)=1200x+2400 \\ x=12 \\ f(12)=1200(12)+2400 \\ f(12)=14400+2400 \\ f(12)=16,800 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/tb70n5jsexkujw79ncfzbp15444o86hc5e.png)
Hence, the amount Karen will pay after living there for 12 months will be $16,800 which is option D