I got 5, 1, 2, for D, can't remember which way round the signs were though. That's good to hear.
for the vector equation of the line, I put in the coordinates of B, whereas most would have put in A. Both are correct, but that means my values of mu swapped around. mu=-1 gave me the coordinates of A, and mu=-2 gave me the coordinates of D. Again, for most people this will be the other way around.