When the body is invaded by a pathogen it starts to make antigens..is this true or false?

True.

When the body is invaded by a pathogen, such as a bacterium or virus, the immune system responds by producing antibodies. Antibodies are proteins that recognise and bind to specific antigens, which are molecules that are found on the surface of pathogens. The binding of antibodies to antigens helps to neutralise the pathogen and prevent it from causing disease.