can someone please help me with this

Step-by-step explanation:
the move from A to C is done via the coordinate change vector (+3, +8). so, x increased by 3, y increased by 8.
that is just halfway to B.
so, we need to apply the same change vector a second time, this time on C, to get to B.
so,
(2, 3) + (3, 8) = (5, 11) = B