Final answer:
In the process of geometric dilation, angle sizes are preserved. Consequently, angle B' would remain the same after dilation.
Step-by-step explanation:
The properties of dilation in geometry tell us that angles are preserved during the process of dilation. This means that no matter how a figure is enlarged or reduced, all of the angles remain congruent to their corresponding angles before the transformation. Therefore, the answer to the question, 'What do the properties of the dilation from problem 5 tell you about angle B'?' would be 'A) Angle B' remains the same'.