The answer is C, 7.5.
This is because you know that these are the same objects, since it’s asking to find the scale factor. You are able to correlate AB to EF, and that shows a scale UP of 1.5, from 2 to 3. With this scale factor of 1.5, we know that EH will be 1.5 times bigger than AD. So 1.5 x 5 is equal to 7.5.