The most relevant response regarding the social context of Huey Long's "Share Our Wealth" speech is:
D. The Great Depression had made people desperate for solutions.
This option highlights the urgency and despair of the time, which prompted Long's proposals for wealth redistribution and social welfare measures as remedies for the economic hardship faced by many Americans during the Great Depression. While options A, B, and C contain accurate information, they do not directly address the social context that influenced Long's speech and the public sentiment at the time.