Let the function \(g(x)\) be defined by \(g(x) = 2f(x) + k\) , where \(f(x)\) is a linear function. If \(g(2) = 10\) and \(g(5) = 18\), what is the slope of function \(f\)?
(A)\(\frac { 2 } { 3 } \) (B)\(\frac { 4 } { 3 } \) (C)2 (D)3 (E)\(\frac { 9 } { 2 } \)
B