If $\bar {x} $ is the mean of ten natural numbers $x_1,x_2,x_3......x_{10}$ , then $(x_1 - \bar {x}) +(x_2 - \bar {x})+ ..... (x_{10} - \bar {x} )$ is _______

Question

$(A) \; n \\(B)\; n \bar {x} \\(C)\; 0 \\(D)\;none\;of\;the\;above $