Name the intersection of plane acg and plane bcg
a. ac
b. bg
c. cg
d. the planes do not intersect

c. CG
  In the given problem, the place ACG and plane BCG. These planes intersect at CG in which intersection is either a point, line or curve that an entity or entities both possess or is in contact with. In the plane we can understand that the common line for both plane ACG and plane BCG is CG. Further examples can include, plane KTGX and plane KUYT, in this case you can imagine a rectangular prism in which they both intersect at line KT.

(-0, -7) is your answer