Identify the Fallacy in the Following Argument: "All Acts of So-Called

Identify the fallacy in the following argument: "All acts of so-called altruism, including Luigi's heroism, are motivated by psychological egoism. After all, you cannot prove that Luigi, who ran into a burning building to save a child, was not acting purely out of self-interest."

A) accident
B) appeal to inappropriate authority
C) hasty generalization
D) ignorance