Which is an indication that a source is credible?

the source was published 20 years ago

the source uses inflammatory language and stereotypes

the source is published in a reputable magazine

you cannot find information about the author's credentials

The indication that a source is credible is: The source is published in a reputable magazine. When it is published in a well-known magazine, people would consider it as a reliable source because the reputation of the magazine is high. If the source was published 20 years ago, its contents might be obsolete and many changes have been made along the years. It should not contain stereotypes and inflammatory languages as well.