During the 1980s and 1990s, the annual number of people who visited the Sordellian Mountains increased continually, and many new ski resorts were built. Over the same period, however, the number of visitors to ski resorts who were caught in avalanches decreased, even though there was no reduction in the annual number of avalanches in the Sordellian Mountains. Which of the following, if true in the Sordellian Mountains during the 1980s and 1990s, most helps to explain the decrease?

(A) Avalanches were most likely to happen when a large new snowfall covered an older layer of snow.
(B) Avalanches destroyed at least some buildings in the Sordellian Mountains in every year.
(C) People planning new ski slopes and other resort facilities used increasingly accurate information about which locations are likely to be in the path of avalanches.
(D) The average length of stay for people visiting the Sordellian Mountains increased slightly.
(E) Construction of new ski resorts often led to the clearing of wooded areas that had helped to prevent avalanches.