Find All Points of Inflection of the Graph of the Function

Multiple Choice

Find all points of inflection of the graph of the function $f ( x ) = 2 \sin 7 x + \sin 14 x \text { on }$ the interval . Round your answer to three decimal places wherever applicable.

A) $( 0.26,1.452 ) , ( 0.449,0 ) , ( 0.637 , - 1.452 )$
B) $( 0.282,1.11 ) , ( 0.669 , - 0.004 )$
C) $( 0.449,0 ) , ( 0.637 , - 1.452 )$
D) $( 0.26,1.452 ) , ( 0.449,0 ) , ( 0.659 , - 1.794 )$
E) $( 0.26,1.452 ) , ( 0.637 , - 1.452 )$