Modifier 62 Is Assigned in Which Scenario

Modifier 62 is assigned in which scenario:

A) During an anterior thoracic spine procedure, the neurosurgeon requests that a thoracic surgeon create the approach to the spine
B) A neurosurgeon requests the assistance of a nonresident surgeon for a difficult and extensive procedure for which no available residents are qualified to assist
C) During coronary artery bypass, the cardiothoracic surgeon gains access to the site while the assisting surgeon harvests the saphenous vein
D) During coronary artery bypass, the cardiothoracic surgeon gains access to the site while the assisting surgeon harvests the saphenous vein and provides additional assistance as needed throughout the entire procedure