The triangle in Quadrant III is the image of the triangle in Quadrant IV after a counterclockwise rotation about the origin. What is the angle of rotation?

As per given by the question,
There are given that the triangle in quadrant III.
Now,
From the quadrant III, there are given a triangle.
Then,
If we wiil rotate the triangle on counterclockwise or anticlockwise direction , then it will be matched with given triangle on fourth quadrant at angle of 90 degree.
Hence, the option A is correct.