I voted C, because I think it is highly misleading to speak of Japan as a whole wanting anything from Nomonhan. Part of the reason for Japan's suicidal descent into WWII is that the Japanese didn't have an especially unified foreign policy; junior officers could do what they wanted, and the government had to respond. This tendency was most obvious in China (see the Mukden Incident, for example), but appeared elsewhere as well, and also acted to more subtly constrain Japanese policy making. Even though China was widely acknowledged to have turned into a quagmire by this point, any plan that seemed to admit defeat risked the policy-maker behind it suffering an assassination.
Nomonhan, for instance, was the result of escalations by the Kwangtung Army, without central direction. Tokyo wasn't initially calling the shots, and once it started they had internal disputes over where to go. The officers in the Kwangtung Army would probably have been happy enforcing the Japanese-supported border at first, but would not have objected to winning more land if possible (compare to the Japanese escalation/expansion in China, which also saw goals constantly changing).