Final answer:
The correct statement is that an air taxi operator engaged in providing a commercial air service may not conduct an IFR flight if an alternate has not been designated in the IFR flight plan or flight itinerary.
Step-by-step explanation:
The correct statement out of the options provided is a) an air taxi operator engaged in providing a commercial air service may not conduct an IFR flight if an alternate has not been designated in the IFR flight plan or flight itinerary. In Instrument Flight Rules (IFR), an alternate airport is required to be designated in the flight plan to ensure that there is an alternative landing option in case the intended airport is unavailable due to weather or other reasons.