if they are indoors and no one smokes, it's highly unlikely.
it's way past its time in that solo cup, most likely the cause. i'd transplant it into something bigger and see if it recovers..

one rule i like to use when knowing whether it's time to transplant is when most of the leaves reach the edges of the cup. based the photo, i would of transplanted maybe 3 weeks ago.

No evidence of that virus in your photos. Mosaic virus causes a pattern of tiny dots, looking much like a mosaic of small tiles, beads, etc..

Yeah, being inside it's almost clear it's not a virus. Also, it doesn't look quite like some viruses. If it would pretty much stop growing, it might be, but I doubt that will happen.

It's most likely fertilizer/pH related. I would stop the fertilizer for now.

It looks like either your roots are damaged, and/or it got some surprise exposure to strong sun/light.

Did you get the leaves wet? Sometimes plants prone to edema will do something like that when they get wet (but they'd probably get yellow bumps, too, if that were the case).

It could be general stress from whatever is or isn't in the soil, as others have noted.

Unless your soil/containers were infected, or unless you have pests feeding on your plants, or unless you smoke and touched the plants, then it's probably not a virus.

I agree, it was a soil issue. I planted them in the garden yesterday, and the leaves have grown much larger and greener. Hopefully no more major issues will arise anytime soon.

they just needed to be transplanted as i originally mentioned.
plants become stressed when their roots no longer have the space they need, and develop all sorts of symptoms. solo cups should only be used during the first 2-3 weeks of growth, then they should be transplanted into something bigger.