Question 20 What is the allowable gap between members of a barrier to a re-isolated stair? (a) Gaps such that a 125 mm sphere could not pass through the barrier. (b) Gaps such that a 100 mm sphere could not pass through the barrier. (c) There is no requirement for gaps for barriers to re-isolated stairs. (d) Gaps such that a 300 mm sphere could not pass through the barrier