The correct option is C 8x3y+11x2y2+3xy3+3x3+12y2+6xy
x3y+4x2y2+3xy3+7x2y2+3x3+4y2+6xy+7x3y+8y2 is the given expression.
Now, x3y and 7x3y are like terms.
Hence they can be added to give 8x3y.
Similarly, 4x2y2 and 7x2y2 are like terms.
They can be added to give 11x2y2.
Also, 4y2 and 8y2 are like terms.
They can be added to give 12y2.
Thus, the final simplified expression is
8x3y+11x2y2+3xy3+3x3+12y2+6xy.