I am making a game but I have recently faced a problem ,my coding eror stats that PrevOption undefined which I do not know what it means
Can you show us a screenshot?
We’d be glad to help out.
It sounds like it could mean that it’s trying to reference a variable called “PrevOption,” but that such a variable doesn’t exist. Maybe make sure that the spelling is consistent? It’s also case sensitive. If that’s not the issue, then yes, like @Carlos.R says, showing us would make it easier to determine the problem. If you could copy the part of the code where the problem is, that should help 
It could mean that there is no variable named PrevOption but if you can provide the screenshot of error message and that part of code a more accurate cause and solution can be given