Recall we're looking for an answer choice that helps us resolve the paradox in the stimulus. The first half of the stimulus tells us that there's been a substantial decrease in timber jobs. The second half of the stimulus tells us that there's been a substantial increase in wood taken from the forests.
Maybe there has been a shift in Ravonia's timber jobs. We're looking for an answer that helps us to reconcile both halves of the paradox.
(C) says, "Since 1977, a growing proportion of the timber that has been cut in Ravonia has been exported as raw, unprocessed wood."
(C) has some very interesting implications. If there has been more wood that has been exported as raw, then there must be a smaller proportion of the wood that has been and is being devoted to processing, which would account for the loss in jobs. However, if there has been more and more timber cut raw, this also helps to explain the increase in the timber harvest, too. Thus, (C) resolves the paradox for us.
Hope this helps. Let us know if you have any other questions!