The use of dwangs has evolved as light timber-frame construction methods have changed. What is the definition of a dwang, nogging or blocking? Select one: a. A piece of timber of rectangular cross section between 15 mm and 40 mm thick b. A material applied as flashing to divert moisture c. A vertical member providing the support for the top and the bottom of a bearer d. A member that makes a negligible contribution towards the racking resistance of walls