People with a strong external locus of control are best described as believing that

The correct answer is - their fate is a matter of happenstance.

People who have a strong external locus of control tend to believe that everything that happens to them is out of their hands, that it depends on somebody or something else other than themselves. They might believe that it is a coincidence/fate that something happened to them, regardless of the fact whether or not they put any effort to make that happen.