Suppose $p(x)=x^2+5x+3$ and $q(x)=3x^3-3x+7$. Write the expression $(q \circ p)(x)$ as a sum of terms, each which is a constant times the power of $x$.

Here is my work for the problem:  

$(q\circ p)(x)=3(x^2+5x+3)^3-3(x^2+5x+3)+7$  

$(q\circ p)(x)=3(x^6+125x^3+27)-3x^2-15x-9+7$  

$(q\circ p)(x)=3x^6+375x^3+81-3x^2-15x-2$  

$(q\circ p)(x)=3x^6+375x^3-3x^2-15x+79$  

Did I do something wrong while working with this problem? The final answer I got wasn't in the multiple choice answers. I went over this problem 3 times and cannot find what I am doing wrong.