Correct option is (d) Wooden
Easiest explanation: There is no wooden plaster finish available. Rough-cast is provided to the external surface using 1:1:3 mortar (cement:sand:coarse aggregates). Pebble or flint dash finish involves embedding 10-20mm sized pebbles or flints in 12mm thick plaster. Sand faced finish is provided with 1:1 mortar.