To make a strong argument, the writer or speaker must avoid? logical reasoning. logical fallacies. logical support. logical statements.

To make a strong argument, the writer or speaker must avoid logical fallacies.

This is because a fallacy is something that is untrue, thus if it was logical your reader might be persuaded against your argument. Basically, as a writer you don't want to contradict yourself and you only want to support one side of an argument.

Hope this helps! :)