Oh yay, proportional thinking! (Vicious sarcasm). Alright, let's do this:
<span>Volume of the cylinder = </span><span>π(h)r^2 New volume = </span><span>π(h/3)(4r)^2 = (1/3)</span><span>π(h)(16r^2) =16*(1/3)</span><span>π(h)r^2 =(16/3)</span><span>π(h)r^2
Therefore, it's D. Though it's spelled pi, and you should really use the ^ symbol. </span>