No. Zachary should have drawn the first two arcs with the compass centered at B.
Yes. Zachary correctly constructed the median from C to AB¯¯¯¯¯¯¯¯.
No. Zachary should have drawn the second pair of arcs using a different compass width.
Yes. Zachary correctly constructed the median from A to CD¯¯¯¯¯¯¯¯.