Number a is a correct one
A block has a volume of 0.09 m3 and a density of 4,000 kg/m3. The force of gravity acting on the block in water is 3,528 N. density = mass / volume , mass= 4000*0.09 =360 kg , force = mass *acc , force = 360 *9.8 = 3,528 N
A)3528 N