C is opposite from where on the triangle?

Answer: Option 'B' is correct.
Step-by-step explanation:
Since we have given that ABC is a triangle.
In which we need to find ∠C is opposite to AB.
As we can see from the figure that Side AB is just opposite to ∠C.
Similarly, ∠B is just opposite to side AC.
And ∠A is just opposite to side BC.
Hence, Option 'B' is correct.