For an existing inspection lot tied to a delivery item (e.g., inspection type 10) with no results recorded:

Change the Actual Lot Quantity of the Current Inspection Lot (A): If the delivery item quantity changes (VL02N), the system updates the inspection lot's quantity to match (status CRTD or INSP), as long as no results are recorded. This maintains synchronization without creating a new lot (SPRO > QM > Quality Inspection > Inspection Lot Creation > Define Inspection Lot Update).

Cancel and Create a New One (B): Cancellation and recreation occur only if the item is deleted, not just quantity-changed.

Create a New Inspection Lot (C): A new lot isn't created for a quantity change; the existing lot adjusts.

Block the Current Inspection Lot (D): Blocking isn't triggered by quantity changes in this scenario.

Thus, 'Change the actual lot quantity of the current inspection lot' is the correct answer.