Final answer:
The subject of this question is Social Studies. It asks for the opinions of adult Americans regarding government spending on sending humans to Mars.
Step-by-step explanation:
The subject of this question is Social Studies. The question is asking for the opinions of adult Americans regarding whether the government should spend additional money to send humans to Mars in light of the huge national deficit.
This question falls under the domain of Public Opinion within the field of Social Studies. Public Opinion is the collective attitudes and beliefs of individuals on certain issues in a society. This question explores the opinions of adult Americans on a current issue related to space exploration and government spending.
Examples of related topics in Social Studies include government policies, public opinion polls, and decision-making processes within a society.