A "Header" Is a Transverse Raceway ____

A "header" is a transverse raceway ____.

A) that forms a continuous, unbroken conductor connecting individual outlets
B) in a cellular metal floor, that may be approved as enclosures for electric conductors
C) within rigid tubing enclosed in tubular space whose axis is parallel to the axis of a metal floor member
D) for electric conductors, providing access to predetermined cells of a cellular metal floor