Final answer:
Ann's action of digging up her irises from her house's yard to move them is an act of severance. Severance is when fixtures are separated from the land to become personal property once more. This is contrasted with annexation, which is not applicable in this real property context.
Step-by-step explanation:
The student's question pertains to the concepts of severance and annexation as they relate to real property. In this context, severance is the act of separating fixtures (items of personal property that have become attached to the land) from the land, making them personal property again.
On the other hand, annexation usually refers to the addition of territory into a larger entity, such as a city or nation, this term is not the correct choice for the given scenario. Considering the provided definitions, the correct term for Ann's action of digging up and removing her irises is severance, because she is detaching the irises (which could be seen as part of the land) to make them personal property again.