Answer: Monitor C is the different one.
Step-by-step explanation:
The aspect ratio is the relationship between width and height.
So we only need to see the quotients between width and height for each monitor and see which quotient is different.
Monitor A:
Quotient = 1152/864 = 1.333....
Monitor B:
Quotient = 800/600 = 1.333...
Monitor C:
Quotient = 1920/1080 = 1.777...
Monitor D:
Quotient = 1600/1200 = 1.333...
We can see that the one with a different aspect ratio is monitor C.
