The man who comforts George Wilson after Myrtle's death is Michaelis.
Michaelis is a Greek immigrant who runs the coffee business beside Wilson's garage in the valley of ashes. After Myrtle is struck and killed by the yellow car, Michaelis stays with the devastated George through the night. He brings him coffee, listens to his confused statements, and tries to persuade him that Myrtle's death was an accident.
Michaelis is more than a minor witness. His account helps Nick reconstruct the moments before Myrtle ran into the road, and he notices details that George interprets differently. When Wilson discovers a dog leash that he believes proves Myrtle's infidelity, Michaelis offers innocent explanations, but Wilson has already become convinced that another man caused her death.
The other options refer to unrelated figures or names. Doctor T. J. Eckleburg is the giant billboard overlooking the valley of ashes, not a person who comforts Wilson. McKee is a photographer associated with Tom's apartment party, while Wilson's father is never presented as the grieving companion in this scene.
Michaelis remains with Wilson until dawn, but he cannot prevent Wilson from seeking revenge against Gatsby, whom Tom has misleadingly identified as the car's owner.