Question 677086
h = w + 4
Therefore, w = h - 4

l = 3w = 3 * (h - 4)

V = lwh 
{{{V = (3*(h-4)) * (h-4) * h}}}
{{{V = 3 * (h-4)^2 * h}}}
{{{V = 3h * (h^2 - 2*h*4 + 4^2)}}}
{{{V = 3h * (h^2 - 8h + 16)}}}
Therefore, 
{{{V = 3h^3 - 24h^2 + 48h}}}
which is A