The parent function is the easier way to write the equation, so for a line is:
now we know that if the constant next to x is:
a > 1 then the graph will be stretched.
if 0 < a < 1 then the graph will be compressed.
and if a < 1 then there will be combination of a vertical stretch or compression with a vertical reflection.
this means that the answe is F because 2/3 is between 0 and 1 so the correct form is: