Final answer:
Actual cash value is determined by considering all relevant factors using the broad evidence rule. Therefore, the correct option is A.
Step-by-step explanation:
The rule under which actual cash value is determined by taking into consideration all relevant factors an expert would use to determine the value of the property is the broad evidence rule. This rule allows for a comprehensive evaluation of the property's value, including factors such as market conditions, replacement cost, depreciation, and other relevant data. It ensures a thorough and fair assessment of the property's worth.