question_answer

The number\[{{p}^{5n}}-1,\]where n is a positive integer is always divisible by:

A)  \[p+1\]            

B)  \[p-1\]

C)  \[p+1\]and\[p-1\]          

D)  \[{{p}^{2}}+1\]

E)  None of these