Which magnification factor would create the greatest amount of size distortion?

A magnification factor refers to how much larger an image appears compared to its actual size. The greater the magnification factor, the more enlarged the image becomes, which can lead to a greater possibility of size distortion. This distortion occurs because as the image is magnified, it may not scale uniformly, especially if the imaging system isn't calibrated or used correctly.

Among the given magnification factors, a factor of 2.56 presents the highest level of magnification. This means the object will appear 2.56 times its actual size. The higher the magnification, the more significant the potential for size distortion due to over-enlargement, which can lead to issues in accurately interpreting the size and shape of the objects being imaged.

Magnification factors such as 1.5, 1.8, and even 2.0 will create less distortion relative to 2.56 because they impose less enlargement. Thus, the magnification factor of 2.56 would indeed result in the greatest size distortion, making it the correct answer.