If you have more than enough crawlspace venting, you could simply cut away the screen from one of the existing foundation vents and install a dryer vent in its place. As long as the dryer duct pipe is not excessively long (allowing moisture to condense or lint to settle), that should suffice.
Otherwise, cut another hole in the crawlspace perimeter for a proper dryer vent, one without a screen, and run the duct pipe to it.
Either choice should meet with the inspectors approval. But if you have doubts, ask him/her to confirm that your plan is OK.
I think you won't want to vent through the roof since lint and humidity don't travel well uphill. The water vapor will probably condense as it encounters unheated pipe, and as the condensate mixes with the lint, the resulting slurry will flow backward and deposit itself messily along the bottom of the pipe.