If It Takes an Average of 14 Billion Years Before

If it takes an average of 14 billion years before any proton inside the Sun will undergo fusion, and the Sun is only about 5 billion years old, why do astronomers believe that fusion is going on there now?

A) fusion begins with particles even lighter than protons, which fuse more easily
B) there are an enormous number of protons inside the Sun, and some of them will fuse much sooner than the average
C) much more fusion takes place in the hot atmosphere of the Sun (where it can happen faster) , not deep inside (where fusion is slow)
D) most of the fusion inside the Sun involves carbon, not protons; carbon fuses much more quickly
E) there is no fusion going on inside the Sun, and the fact given in the question is one of the reasons why