Which was the reason Samuel Gompers gave for limiting membership in his union to skilled workers?

Skilled workers would make a powerful union because it was costly to train replacements.

Skilled workers did not wish to mingle with unskilled workers, African Americans, and immigrants.

Skilled workers were more likely to gain the respect and support of Congress than unskilled laborers.

Skilled workers made more money and could afford to be out on strike for longer periods than unskilled workers, giving them more power.