A Gel Electrophoresis Is Performed, but When the Gel Imager

A gel electrophoresis is performed, but when the gel imager is used, a single large band appears at the site where the samples were initially injected into the gel. What is the most probable cause and why?

A) No electrical current was added and therefor the negative charged DNA did not move towards the positive node.
B) The gel was facing the wrong node and positive charged DNA was attracted to the negative node stopping it from moving.
C) The current was too high increasing the negative charge of DNA keeping it from moving into the gel.
D) Too much DNA dye was added making the DNA fragment too heavy to move through the gel.