A Nutanix vDisk live migration moves the VM’s virtual disks into a new storage container while the VM remains online. For that to complete, the destination container must have enough available capacity to receive the migrated vDisk objects. If the target container lacks space, the migration can stall or fail because Nutanix cannot fully place the destination copy and complete the handoff. This makes insufficient storage space in the target storage container the most direct explanation. Nutanix migration and storage workflows consistently rely on adequate target-side capacity before the move can finish successfully. ( portal.nutanix.com )

The distractors are less precise. Source-side snapshots can be part of protection or internal workflow behavior, but the question is specifically about moving to a new container, so target capacity is the key gating factor. “Local storage container” is too vague and is not the normal object referenced in this workflow. Operationally, the right next step is to confirm free space, reservations, and any capacity constraints on the destination container before retrying the migration. That is why B is the best answer.