Find the domain of the function. \[ f(x)=5 x+3 \] $(-$ ,0) (A) $(0$, ) 10, (B) ) $[-3$ (c) ) (- (D). )

Step 1 ：To find the domain of the function, we need to determine the possible values of x for which the function is defined. Since this is a linear function, it is defined for all real numbers.

Step 2 ：\(\boxed{(-\infty, \infty)}\)