Use Function Notation to Write the Equation of the Line $\frac { 2 } { 5 } ; y$

Use function notation to write the equation of the line with the given slope and y-intercept.
-Slope $\frac { 2 } { 5 } ; y$ -intercept $( 0 , - 8 )$

A) $f ( x ) = \frac { 2 } { 5 } x + 8$
B) $f ( x ) = - \frac { 2 } { 5 } x - 8$
C) $f ( x ) = 2 x - 40$
D) $f ( x ) = \frac { 2 } { 5 } x - 8$