Theorem: A line parallel to one side of a triangle divides the other two proportionately. In the figure below, segment DE is parallel to segment BC and segment EF is parallel to AB:
Which statement can be proved true using the given theorem? (6 points)
Select one:
a. Segment BF = 16
b. Segment BD = 20
c. Segment BD = 15
D. BF = 32
(Not b)