Think of the entire population of 6th graders here. 3/7 are boys and 4/7 are girls. 5/8 of these boys are in Ms. Jones' class; that fraction would be (5/8)(3/7), or 15/56. This 15/56 represents the fraction of the entire sixth grade class who are in Ms. Jones' class.
Through a geometric proof, 2(55x-1) = 107x+1
110x-2=107x+1
3x=3
x=1
Angle DEF is 54 degrees.
D would be the best option in my opinion