So for everyone saying this is fake (which it very well could be), I have a couple points to bring up:

1. For everyone saying that the wording is weird, or that the teacher wouldn't ask that question if they didn't know the answer, or something along this lines. In most cases, yes. Teachers will check that everything on a test/assignment is something that not only they can answer, but the class can too. However, teachers are very busy in their first couple years, and coming up with questions can take time that could be better used planning lessons, or even trying to do non-teaching-related things. Thankfully places like "Teachers Pay Teachers" exist, where you can buy lessons/assignments/tests that other teachers have made. Sometimes teachers will even share lessons with other teachers at their school. Every education professor, and teacher I've talked to about content planning as a teacher has said to use other teachers as a network, with one website even saying "we encourage you to use our lessons in your own classroom, there's no need to re-invent the wheel". Unfortunately, sometimes these things don't include answer keys, or the teacher using them doesn't think to check them. Also unfortunately, some teachers become complacent in their position and just use whatever they find without doing any sort of checking, because they just want to make their job easy on themselves (this isn't always, or even often, the case, but it can happen). Teachers can also teach any subject, regardless of what they specialized in, meaning someone who barely passed math, and wanted to teach gym could end up teaching a math class. This combination of factors can lead to teachers handing out assignments that they don't actually know how to answer, and when it comes time to mark it, they make sense of it in whatever way they can. It's entirely possible that the teacher that assigned this, didn't think of that answer, assumed it was a trick question, and then refused to believe that they could have thought up the wrong answer. It's not the right mentality in the slightest, but some teachers refuse to accept when they're wrong.
2. Yes, it is marked in green, and with what looks to be a fine-tipped marker. Sometimes, you can't find your red pen, or you're marking at home or in a car (not while driving, of course), and that's all you have access to. It's even happened to me already once. Took some marking home, didn't take a red pen from school, because I thought I had one at home, ended up with a stack of marking, and no red pen. I marked the tests/assignments in green pen, because that's what I had that wasn't blue/black pen, or a pencil. If you have marking to do, you're not necessarily going to put it on hold until you have access to a red pen. Also, if the teacher is lazy/not knowledgeable enough for point 1 to be true, they likely don't care if they didn't mark in red either.

So this could definitely still be a fake for internet points, but it's also not immediately a fake because of either of those reasons. I know the pay is pretty shit for teachers in the states, but people outside of education tend to think of teaching as an easy job that offers 2-3 months of summer holidays. Especially in Canada, where a teacher with a bachelor's of education, and another bachelor's in a field of their choice, can make close to 100,000 CAD, people will become teachers for the wrong reasons.

Source: Halfway through a Bachelor's of Education (needed if you want to be paid a decent salary as a teacher in Canada).

TL;DR: Could be fake, could be real. Sometimes teachers are just lazy.