Which of the Following Are Examples of Erosion

Which of the following are examples of erosion?
I. The loss of sales due to increased competition in the product market
II. The loss of sales because your chief competitor just opened a store across the street from your store
III. The loss of sales due to a new product which you recently introduced
IV. The loss of sales due to a new product recently introduced by your competitor

A) III only
B) III and IV only
C) I, III and IV only
D) II and IV only
E) I, II, III, and IV