Answer:
8 and 7
Explanation:
For a dilation to produce a larger picture than the original, the scale factor must be greater than 1. I assume an expansion means a larger picture, so 7 and 8 fit this criteria.
For future reference, for it to be smaller than the original, the scale factor must be between 0 and 1. That means that 0.8 and 0.7 will both produce images that are smaller than the original.