Final answer:
The correct option to determine if there is encroachment on a property is a survey.
Step-by-step explanation:
The correct option to determine if there is encroachment on a property is C. survey.
A survey is used to identify the boundaries of a property and ensure that no encroachments have occurred. It involves measuring and mapping the property to determine its legal description and boundaries. By conducting a survey, property owners can identify and address any encroachments on their property.