This is a good restatement of the conclusion. The rest of the argument supports this by showing that Baumgartner has neglected vital considerations.

This is premise. It provides support for the idea that including the use of different cars is necessary to accurately compare environmental impact.

The author claims that Baumgartner is considering an incomplete set of information. That’s not the same as inaccurate data. Baumgartner’s production data may be 100% accurate, but the resulting comparison is still misleading.

This is a sub-conclusion. Because the total life cycle is what matters, Baumgartner is using incomplete information when he only considers production. (D) supports the conclusion that Baumgartner’s comparison is misleading.

The author doesn’t address this. We know that the author believes that gas-powered cars use more resources, but we can’t assume that the author also believes they create more environmental hazard.