“Fender bender” means ________ ?

When I am alone, I hear the footsteps of my friend in my imagination.A. The footsteps of my friend heard by me, when I am alone.
B. The footsteps of my friend is heard by me when I am alone.
C. The footsteps of my friend are heard by me when I am alone.
D. The footsteps of my friend was heard by me when I am alone.