Hi! Combining all the rules we have here, we would get the following chain statement:
W -> G -> not H -> not J (->S) and not M
So if we have G in the forest, we start at G from left to right in this chain which means we don’t have any information about whether W is in the forest or not since it comes before G in this chain, therefore it is not a must be true answer choice. So yes, you are correct in your assessment that we only know not H (and not J, S and not M) from G being in the forest - W does not necessarily have to be in the forest. Hope this helps!