please answer 10,11, and 12!

What is the role of NBS in allylic bromination? A. A source of chlorine B. A source of Bromine C. A source of Nitrogen D. A source of vibration QUESTION 11 Allylic bromination generally happens faster at a more substituted site. True False QUESTION 12 Allylic bromination takes place via which type of mechanism? initiation, propagation and termination Polar heterogenic heterolytic