Fill in the blank with the appropriate answer.
Faceplates provided for snap switches mounted in boxes shall be installed so as to _________ cover the opening, and where the switch is flush mounted, seat against the finished surface. Any gaps or open spaces at the edge of a box installed in a non-combustible surface shall be repaired if _________.
A) completely / if the gap is greater than 1/8 in.
B) formally / if the gap is greater than ¼ in.