In synthetic division, you start by bringing down the first 1 in the box. Multiply that by the 1 outside the box and get a 1. Put that new 1 under the 2 inside the box and add to get 3. Multiply the outside the box by that 3 to get 3 and put that new 3 under the -3 in the box and add to get 0. Multiply that 0 by the 1 outside the box to get 0. Put that 0 under the 2 and add to get the remainder of 2. Your answer is 2, C.
I used a triangle generator, see picture attached
3.9
×104
_____
405.6
8.7
×102
_____
887.4
