Let [x] denote the greatest integer not exceeding x and {x} = x -[x].
If n is a natural number, then the sum of all values of x satisfying the equation 2[x] = x + n{x} is

A

$$\frac{n(n+1)}{2}$$

B

n

C

$$\frac{n(n+2)}{2}$$

D

$$\frac{3}{2}$$