I was in the same boat with the October LSAT. I knew i wasn't ready and was going to score low, but I took it anyways. Honestly, im happy I did. Taking the test for the first time makes you feel a kind of nerve that NO practice test can prepare you for, but now that ive taken the real test, I feel a lot more confident. Not only that, but taking the real test gave me an even better idea of what I am weak at. With all the studying ive done, and with 2 more months of prep left until the January LSAT, I feel even more confident that I will do well on it.

Also you never know. You could just happen to have an extremely good/lucky test day in January and score really well. You've already paid for it so might as well give it a shot!

I chose D simply because I thought the assumption the argument was making was

if the NA manufacturers produced more cars, then the Japanese customers would actually buy these cars, therefore bringing balance to the trade imbalance.