Translation:They will not park because they do not have a car.
Yes, mar could be translated as either “as”, “because”, or “since” in this sentence. If “as” wasn’t accepted, did you report it as an error?
my audio isn't working on this sentence any time it comes up in this section, though the others do.
I think so. It's never happened before. I logged in and out of Duo several times but it always happened on the same questions so I gave up and went to other modules, which worked fine.