Which of the following is true ?

A. in OpenGL polygons have to be convex (outside angle at each corner is >180 deg)

B. the face normal of a primitive is used for texturing

C. each texture coordinate is multiplied with the GL_MODELVIEW matrix automatically

D. back face culling is a way to increase rendering performance

E. lighting calculations are only done for vertices

F. the front and back face of a primitive is defined by its normal

Hey guys, need help again…

I am 110% that these are true: A. and D. but i am not sure about the rest. Can anyone help?