A nations power based on wealth is called is usually referred to as GDP, or "Gross Domestic Product" (if I'm understanding the question correctly. Although this isn't always a great indicator of the fundamental "health" of the country.<span />
<span>One reason historians can rely on government records for accurate historical information is that government records tends to be telling the truth since these data are also used by the people in that time which requires them to write factual data. Hope this answers the question.</span>
I'd have to say C. The whole thing around McCarthy was him accusing people of being communist
