A.\({f_2} = \sqrt 2 {f_1}\)
B.\({f_2} = \dfrac{4}{3}{f_1}\)
C.\({f_2} = \dfrac{{\sqrt 3 }}{{2\sqrt 2 }}{f_1}\)
D.\({f_2} = \sqrt {\dfrac{2}{3}} {f_1}\)