Which of the following would be considered an act of altruism?

Altruism is defined as a selfless concern for the well-being of others, often characterized by acts that benefit others without expecting anything in return. Giving to charity exemplifies altruism because it involves contributing resources, such as money or time, to help those in need. This act is motivated by empathy and the desire to improve the lives of others, aligning perfectly with the essence of altruistic behavior.

The other options do not embody the concept of altruism. Taking advantage of others is purely self-serving, seeking fame typically revolves around personal gain and recognition, and building walls can imply separation or exclusion rather than help or support for others.