What type of insulation is used for work on flat roofs, on basement walls, as perimeter insulation at concrete slab edges, and in cathedral ceilings? a) rigid board insulation b) spray foam insulation c) batt and blanket insulation d) reflective insulation

The correct answer is A

Explanation:

Rigid foam board insulation is the one which comprise of the sheets of polyiso, polyurethane or polystyrene foam which is a closed cell  as opposite of the open cell.

Closed cell board insulation is strong and possesses the higher R value than the open cell insulation.

Rigid board insulation is the kind of insulation which is used for work on the basement walls, on the flat roofs as a perimeter insulation at the concrete edges of slab.