The correct option is B 27
If x + y + z is constant, the product xyz takes maximum value when each of x, y, z takes equal value.
∵a+b+c=13
∴(a−3)+(b−2)+(c+1)=13−3−2+1=9
For the maximum value of (a - 3) = (b - 2) = (c + 1)
=(a−3)=(b−2)=(c+1)=93=3
So, (a−3)(b−2)(c+1)=3×3×3=27