What is the simplified form of the equation 4/5n - 1/5 = 2/5n ?

a.) n = −2
b.) n = 4
c.) n = fraction 1 over 2
d.) n = fraction 2 over 3

To answer the given above, multiply the whole equation with least common multiple of the denominators which is 5n. Shown below, 
 
                                           (4/5n - 1/5 = 2/5n) x 5n

                                                4 - 1(n) = 2

                                                  -n = -2, n = 2

The answer is not among the choices, it could have been letter A except that the constant in A is negative. 

The answer is 10 bud