The correct option is D 80 kg
Density of raft = 600kg/m3
mass of raft=120kg
Volume of wood =120600m3 =15m3
So, Total upthrust from water if the raft is fully dipped in water 15×1000kg/m3 =200 kg
So, the raft will sink if total upthrust = total downward force,
So, weight that can be (200−120)kg=80 kg