You Are Reviewing a Building Backbone Design with a Vertically

You are reviewing a building backbone design with a vertically aligned telecommunications room (TR) . In the spec you note in a footnote with details that the slots at one end of the telecommunications room (TR) must be flush with the floor and the sleeves provide at the end of the telecommunications room (TR) must also be flush. In your meeting with the electrical engineering firm that has provided the spec, you make the comment that according to best practices, the MINIMUM that slots and sleeves must extend above the finished floor are:

A) 25 mm (1 in) for slots and 51 mm (2 in)
B) 25 mm (1 in) for slots and 25 mm (1 in)
C) 51 mm (2 in) for slots and 25 mm (1 in)
D) 51 mm (2 in) for slots and 51 mm (2 in)
E) 64 mm (2 1/2 in) for slots and 64 mm (2 1/2 in)