Final answer:
The primary focus when moving triangle ABC in a GeoGebra activity is likely on C) Understanding the properties of translations, which involves moving the shape from one location to another without changing its orientation or size. (Option C).
Step-by-step explanation:
When moving triangle ABC in a GeoGebra activity, the primary focus could be on any one of geometric transformations like translations, rotations, reflections, or dilations. Without additional context, it is challenging to determine with certainty which specific property is being investigated.
However, if we interpret moving the triangle in the sense of changing its position without altering its size or orientation, then the most likely focus would be C) Understanding the properties of translations.
During translations, a shape is moved from one place to another without rotating or flipping it, maintaining the same orientation and size.
If the activity specifically mentioned rotating the triangle around a point or altering the angle of the edges which might indicate a focus on exploring rotations, or if it required flipping the triangle across a line which would suggest investigating reflections, or even resizing it which implies looking into dilations, the focus might have differed. But based on the information provided, translations seem to be the most likely primary focus.