Right option is (a) 1
The explanation: Density of substance D = m/v = -v^2 + 3v – 2, => Specific gravity of substance S = D/0.25 = 4(-v^2 + 3v – 2), => dS/dv = 4(-2v + 3) = 0, => v = 1.5, => S is maximum at v = 1.5, => maximum specific gravity = 4(-1.5^2 + 3*1.5 – 2) = 1.