There are three possible endings to my short story, please choose one...

The Other The year is 3000, the 3rd day of the 3rd month at precisely 3pm... The world has inevitable succumb to nuclear devastation but ultimately it was the viral epidemic of an unknown source in the year 2666 that nearly killed all forms of life. Earth our beloved planet is a desolate space where young Lileth finds herself in isolation confined to a cubicle created to preserve the last of the remaining human life form. Instructed never to leave her surroundings she desperately clings to the only source of communication, her computer. Lileth soon begins her journey devoid of the other, a space more empty, confining and twisted than the cubicle she has lived in all her life.
A final alarm sounds...A warning that a threat to human life is imminent. Unlike all the empty solitude days in her cubicle, this day is different. The window shuts and there is darkness. The sound and light from her computer commence and soon Lileth realizes that she is not alone, that there is someone other than herself. She begins to type. She implores the other to let their whereabouts be known but the other is adamant to follow the explicit directions and rules confining them to their space...a space that has protected them throughout their empty existence.
Time is passing quickly. Lileth is aging. She implores wholeheartedly the other to find her. The other does not respond to her solitude. She can no longer exist and begins to die of loneliness. *There are three possible endings, please choose one:

a. The other is in the room right next door to Lileth. He fears the unknown virus will destroy him. If he does eventually leave the cubicle to find her it will be too late...For Lileth will have truly died of loneliness, a much more deadly outcome than the virus itself. Thus he will inevitably face the same death of loneliness.

b. There is no other. The computer has been programmed to be a companion to Lileth until a cure for the virus has been found because she is the last form of human life. She will either exist within the confines of the cubicle and accept her fate or she will leave the confines of the cubicle.

c. The other is an alien life form. The entity has tricked her into leaving the confines of the cubicle. The alien is also the last of it's kind. The two life forms embrace for the last time and the virus kills them both.