According to Part 135.225, what action cannot be initiated if the airport is reported below minimums?

The correct answer is that accepting clearance for an instrument approach cannot be initiated if the airport is reported below minimums. In Part 135.225, regulations are set to ensure safety during flight operations, especially in poor visibility conditions. Accepting clearance to perform an approach means that the pilot is committing to attempt the landing under the new conditions of visibility. However, if the reported conditions are below minimums, it is unsafe to proceed with the approach as there is a higher risk of not being able to see the runway or navigate safely to it.

The other options represent actions that can still be undertaken even if the airport is below minimums. For example, beginning a descent, although it may not be advisable, can technically be initiated, and proceeding to a holding pattern could be a reasonable decision to wait for conditions to improve or for further instructions. Transferring control to a co-pilot is a standard operational procedure and is not restricted by visibility conditions.