Select the correct answer.
Which transformation will always map a parallelogram onto itself?
A.
B.
C.
a 90° rotation about its center
a reflection across one of its diagonals
a 180° rotation about its center
D.
a reflection across a line joining the midpoints of opposite sides

The figure shows triangle def and line segment bc, which is parallel to ef: triangle def has a point b on side de and point c on side df. the line bc is parallel to the line ef. part a: is triangle def similar to triangle dbc? explain using what you know about triangle similarity. part b: which line segment on triangle dbc corresponds to line segment ef? explain your answer. part c: which angle on triangle dbc corresponds to angle f? explain your answer. asap