設(shè)實(shí)數(shù)a在數(shù)軸上對(duì)應(yīng)的點(diǎn)為A，實(shí)數(shù)b在數(shù)軸上對(duì)應(yīng)的點(diǎn)為B，實(shí)數(shù)c在數(shù)軸上對(duì)應(yīng)的點(diǎn)為C，將點(diǎn)A左移動(dòng)4個(gè)單位與點(diǎn)B重合，將點(diǎn)B向右移動(dòng)6個(gè)單位與點(diǎn)C重合，則代數(shù)式a²+b²+c²-ab-bc-ac的值是

1. A.
   56
2. B.
   36
3. C.
   28
4. D.
   20