"It is our child."
Translation:Det är vårt barn.
vårat is a colloquial form for vårt, which should be accepted as input, but we don't really recommend using it in writing. It shouldn't be shown to you unless you happen to input something that the system thinks is similar to it. The system tries to match whatever you input to the closest accepted answer, so you may get shown things like this sometimes.
It sounds like you got this as the 'select the correct sentence(s) out of three' type of exercise. I hate that type too but as far as I've been able to find out there's no way to disable it – either as a user or for us as course creators. The computer adds them and creates the incorrect options. You just have to choose the correct sentences to get past this type of exercise, I'm afraid.