What moral claim did socialists make in criticizing private profit?

Correct answer: Gaining from others' labour increases inequality and injustice

Socialists made a moral criticism of private profit by arguing that profit gained from other people's labour could deepen inequality and injustice. Their concern was not simply that earning money was always wrong. Rather, they questioned an arrangement in which owners controlled productive property and received profits, while workers who created goods depended on wages and had little control over decisions. They believed economic life should serve collective welfare and social justice.

Option A expresses this claim directly: gaining from others' labour can increase inequality and injustice. Option B wrongly says private profit always creates equality. Option C focuses on the king, although socialist criticism concerned class and economic relations. Option D ignores the connection between ownership, labour, and workers' lives. Since the question asks for the moral claim behind the criticism, A is the correct choice.