The Reason So Many European Place-Names End in Borough,burgh,burg,or Bourg

The reason so many European place-names end in borough,burgh,burg,or bourg was:

A) most of them were established by the powerful Boringian family.
B) the term means "cross-roads," a common place to build a city.
C) the names refer to the fortified centers around which cities and towns were built.
D) boros was an early name for a trade guild.
E) a boroman was a ferry-man who insured safe passage across a river. Most towns with such names were founded around river crossings.