Answer:
The answer is C. 6.4 X 8 in
Explanation:
If the scale factor from the original to the trimmed photo is 5:4
The statement above just means the scale of the old dimension is 5 while the scale of the new dimension is 4.
To get the new dimensions, multiply each of the old dimensions by 4/5
4/5 X 10 = 8
4/5 X 8 = 6.4
Therefore the new dimension is 6.4 X 8 in