If you chose C, well done! "En route" is one of a few hundred words that entered English from French in the 1700s. The French court in the late 1600s and early 1700s was seen as the pinnacle of class and taste, so many English aristocrats began to use and adopt French words to sound stylish. "En route" is one of those words. We borrowed not only the French meaning, but also the French spelling. This word is sometimes misspelled as "on-route" or "onroute," since the first part of "en route" sounds like the English word "on." You can remember it's spelled "en route" by keeping in mind that it comes from French, and both "French" and the "en" of "en route" use an "e."