Aside from the loss meme, this depends on unaccounted for factors:
- C: it's windy
- D: rope is tied
- B: chopper broke loose
You can only really exclude A), because a chopper can't fly in a vacuum.
A place for majestic STEMLORD peacocking, as well as memes about the realities of working in a lab.

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Aside from the loss meme, this depends on unaccounted for factors:
You can only really exclude A), because a chopper can't fly in a vacuum.
The loss virus is only triggered when the picture makes no sense. So this one took a while
Fuck!!! It took me waaaaay too long to get this shit. I'm at a loss as to why I didn't see it immediately.
Why would they even put D ... ah fuck!
Do we have to worry about the loss of ve loss ity?
The answer is D because there's no indication that the rope is untied. The helicopter starts his trajectory but loses control and spins out and crashes, this is the hidden frame

Sounds like that could lead to loss. Of life.
0 is a constant speed.
Yes, but not one where we would typically consider something to be 'flying horizontally'.
Yes, but then it wouldn't be flying "to the right" as it says.
If the helicopter is suspended in the air, it's flying. To the right is simply a frame of reference, if I'm driving to the left then it appears as though the helicopter is going to the right, so the speed can be 0.
~~Why are there two images for B, C and~~
goddammit.
Oh goddammit.
?
Loss
This one was still over my head, but you gave me just enough to look it up. For anyone similarly confused.
I commend you for making it this far on the internet without encountering it.
Im glad my own path to despair has been walked by others.
~~:.|:;~~
Dammit
I'm at a complete loss.
Fuuuuuuuck.
[For people wanting the answerthis was the subject of a Veritasium video.
for people who don't want to click the link
It's B.